About two hours ago I came across this interesting question, and clicked on the title only to discover the skeletal remains of eight top-level comments. My immediate reaction was to wonder what the comments were and what circumstances lead to their removal, as I've seen large swaths of obliterated comments more often in this subreddit than I have in many others.
I understand the commenting rules here, even though I have probably violated them from time to time, but I think it does a disservice to the curious to wipe out weak or poorly cited comments rather than just labeling them as such. Ironically, it leaves us lay-folk who aspire to proper historical verifiability unable to learn from the mistakes of others when you destroy the historical record of a conversation or debate.
Would it be possible to create some comment macros for weak or poorly cited top level comments? Something along these lines would be more than sufficient I think (and I personally learned a lot in the discourse about material/sources in that post). I apologize in advance for not really offering a solid solution to the issue I'm raising, and if commenters are deleting their comments due to downvote aversion (shame on you) or self consciousness then I understand that my assessment of what is happening is entirely flawed, but it's something I've seen with increasing frequency here.
Lastly, thanks Mods for all the work you put into this place, I learn new things here every day.
I understand where you are coming from and I understand the natural curiosity of wondering what all the removed comments were about, but there are two issues with this. One, we remove so many comments that leaving a mod note on each and every one would make the threads hilariously unreadable and would come across as insufferably overbearing. Two, as is so aptly illustrated in the example you linked to, mod notes tend to gather even more crap comments that need to be deleted (as in "says you!", "literally hitler", and such), or else they veer into a discussion of the rules that derails the thread even further.
In a question about women and under-age men posing as of-age men to fight in the World Wars, there has been exactly one reply that address that topic. Instead we got this:
"I don't know about any cases during the world wars but [discussion of women as pirates]"
"/r/mildlyinfuriating"
"Any actual answers?"
"oh my god what the hell happened in the comments"
"This is a great question. I hope someone knows about a WWII Mulan."
And a couple answers that were just wikipedia links to women involved in WWII (but not disguised as men), a speculative answer based on the Geneva convention, and a vague recommendation for a book that may or may not actually be relevant regarding women in warfare but certainly wasn't relevant to the World Wars.
The one reply that did discuss an under-age soldier in WWII was removed because it was basically a one sentence "check out the story of this guy" type answer with a link, violating this rule. Basically nothing was lost that couldn't have been found by googling "Underage + military".
This meta comes up every so often, though I can't seem to find the previous thread. You assume that comment graveyards did at one point contain something of value. This is not the case. I cannot remember the last time I reported a comment that may have been helpful to an aspiring poster. So many deleted comments are "lol sex joke" or "[wikipedia link]". Every deleted post simply cannot have a mod comment, so that means the ones worthy of a warning must be singled out. This is an issue of time, and one of subjectivity, neither of which the mods have much to spare.
FWIW, the focused controlled moderation in this SUB is what makes it arguably one of the best large subs on Reddit IMO.
Don't go changing babe.