I think one can have a real discussion about genuine efforts at popular history, including documentaries, podcasts, magazines, books written by journalists for a general audience, etc. There are other discussions of this on this sub if you search for them. Most historians take the view that popularization in general is a positive thing, because we believe history is important, but of course popularization that is misleading can do damage, so it is not a blank check.
But that is not what /r/HistoryMemes are. Those are just shitposts that happen to be loosely themed around generic historical knowledge at best. Sometimes confusion or falsehoods at worst. If I were being charitable I would suggest that /r/HistoryMemes probably doesn't do much harm because its influence on how people think about history is probably pretty weak. I would be surprised (or saddened) to find that anyone takes it seriously as a form of historical knowledge. It is, as they say, for the lulz. I was going to suggest that /r/HistoryMemes takes history less seriously than /r/LOTRmemes takes LOTR, but having looked at the latter they are about the same quality with regards to the source material — mostly just for shitposting. Don't get me wrong, I'm not against shitposting; there's a time and place for everything.
If people were genuinely using /r/HistoryMemes as the foundation for their historical understanding, then I would have to conclude it is negative, because it would be an utterly flimsy and value-less thing to base them on. That is not a criticism of the subreddit — I honestly do not think those who partake in it, or contribute to it, are trying to really engage in "popular history." They are just trying to make history-themed memes that are amusing to a fairly low common denominator. That's fine. But it's not historical outreach.
There can be useful historical messages in concise, meme-sized formats. One sometimes sees them — they tend to be images and a little text that draw one's attention to overlooked things. Those sometimes contain misleading things, too. It's hard to be accurate and that concise. E.g., the confusion over what exactly Margaret Hamilton is standing next to in this picture (it is not "code she wrote by hand") detracts from it, but its essential argument — that women have made important technical contributions to things like the Space Race — is correct, and that by itself can be a useful thing for prompting more considered thought and attention. It'd be nicer if it was fully accurate, of course.
I suspect that this question could probably do with as many answers as possible, so I'll give my tuppence. I wouldn't say that r/HistoryMemes is very typical of pop history, let alone the actual genre of popular history. I would say that the historians I know personally tend to be only vaguely aware of reddit, and often only somewhat aware of memes (despite some of them having teenage children). The younger people I know who study history do love a good historical meme, but what they typically value is obscurity. That is, the very thing they enjoy is the application of a popular meme format to a relatively obscure piece of history that they themselves know of. I might argue that some of the most successful historical memes are those which are obscure enough to seem esoteric while also being fairly accessible to those who do not specialise in the period in question. The recent popularity of memes concerning the Babylonian copper merchant Ea-nasir would be a good example of this.
From what I've seen of r/HistoryMemes, its content does not usually have the characteristics of the kind of memes people who study the period tend to prefer. The content tends to have fairly broad appeal, and moreover it has a tendency to be quite explicitly politicised. Neither of these are bad things, but I would say that r/HistoryMemes is actually far more interesting as a subject of historiographical survey for historians than it is as light entertainment.
As someone who's now a fourth-year history student, I wouldn't have made it this far without the influence of pop history. Material marketed to folks who are inexperienced (or for those who are just too young to be in the thick of it) is vital for, well, getting people to be experienced. A recent AlternateHistoryHub video asserted that "national anthems are like the anime OPs of countries" and I physically cringed, but I'm sure that metaphor was helpful for somebody!
My personal experience is in the gaming sphere of pop history. The outcomes of existing in that space for years on end run the whole gamut as far as producing a relevant historical education. It's all a matter of mindset. If you're a reddit fan and a history fan, you've probably heard of Civilization, or Europa Universalis, or Age of Empires, and the prolific fanbases thereof. In an effort to be less boring than actual bureaucracy, these games consist of abstractions that attempt to bridge the gap between "fun gameplay" and "the multifaceted, infinitely complex motivators behind human behavior".
As historical teaching tools, all of these abstractions miss wildly. Let's use Europa Univeralis IV's Culture Conversion system as an example. In this game you gain Diplomatic Points each month based on the skills of your ruler in that aspect - this is generalized to mean charisma, foreign relations, stuff like that - and you can spend it, whenever you'd like, to "convert" a minority culture in your realm to your own! Just like that, your Andalucians can be God-fearing Spaniards in a few years' time, and seemingly based on the direct personal action of the King of Spain. If you frequent this subreddit, I'm sure you don't need a historian to tell you how problematic this approach is.
However, there's a diamond in this rough. The obvious result of such simple, 'easy' systems is that they raise questions. Does the ease of doing ___ in a history-based video game relate to the ease of doing so in real history? Does the game give you the same motivations to make decisions that historical rulers had when making those same decisions? The answer, overwhelmingly, is no. Ethnic and religious tolerance in Europe were not monolithically based on a desire to "not get rebels". But the asking of the question is what's relevant, and what springboarded myself and many others into genuine historical study. In the drive to answer seemingly ridiculous questions like "why didn't Spain just throw bird mana at its ethnic tensions", I learned more about history than I ever planned to.
On the other hand, you need to care enough, or to be curious enough, to ask these questions. I hope you never undergo the painful experience of interacting with someone who accepts these abstractions for what they are, and begins retroactively applying them to history. The result is atrocious: commit genocide upon all domestic opposition, only befriend those who are of use to you, enter extreme debt to finance your conquests - besides the immoralities, these are the sorts of events which have disastrous political consequences no video game has yet to accurately represent. To assume that processes like these are the building blocks of a nation is to fundamentally misunderstand history.
All in all, the worst outcome of becoming a History GamerTM is buying into the association of each nation/country with a sort of personality. From Civilization to Polandball, there is an almost natural desire in pop history to instill each nation with a character, a wildly stereotypic representation of that group's historical successes and failures. It's a crude way of explaining why not all groups of people follow the exact same sociopolitical process - in other words, why cultures are different from each other. This bleeds very naturally into a sort of social-Darwinist thought, a wide-reaching conceptualization of history as the "Groups that are Good at Things" exercising their God-given right to dominate the "Groups that are Bad at Things". Rather than history being the sum of human behavior, it becomes a pseudo-spiritual journey to find these "national characters" which, to put it bluntly, are fictions. Most dangerously of all, it leads to people picking those national characters which they think best fit their own lifestyle - like reading a horoscope, or taking a personality test - and espousing that nation's glory on history forums moderated less strictly than this one. Without even realizing it, they become bonafide nationalists, and produce more of the same.
But I digress. While very loud and very toxic, people who decide history is best explained by the abstractions of a video game are well in the minority. I would safely wager that historical content aimed at a wider audience - gamers, in this long-winded example - cause far more good than they do harm. I just thought it'd be fun to explain how these games are sometimes a trap for impressionable teens, such as the person I was in high school, and the thought processes behind the weird nationalism you sometimes encounter on forums for said games.
