No. That assumes that comments inherently have something of value. Single links to other websites, offhand remarks, dirty jokes, and "I'd imagine..." statements have no value here, and their absence tells more about our culture in this sub than their presence would.

You can find good discussion on the necessity of deleting posts here, along with links to similar past threads.

If your question is for discussion directly targeted at this sub, you will want to use the [META] tag. If you are here to soapbox, the thread will likely face deletion.

Dude, I want to explain a few things.

1. All removed comments are retrievable. All mods can see them. All admins can see them. If future historians want them for research they are easily found. Not a case of an Orwellian memory hole.
2. We need to maintain an academic standard. What's the point of removing things to the general public? It's to stop this subreddit from becoming /r/History. Quality controls are necessary.

It's more analogous to removing people who can't or won't contribute anything meaningful to a discussion - or even actively try to sabotage it - from the discussion (or kill their microphone). Or throwing loud people out of the cinema. It's a form of censure, to ensure quality of discussion and readability of it by removing elements that don't add anything of value.

Burning books is a symbolic gesture to distance yourself and your ideology from those elements that your group perceives as detrimental or opposed to attaining the ideals you strive for. It's not meant to remove those words, sentences and ideas, because you cannot. Especially after the invention of the printing press. The Nazis, f.e., admitted so themselves - it was the symbolism that was important, the burning of that which they perceived to be 'un-german', not that some books got turned unreadable. It's not a form of censure. When Luther burned the Papal Bull and the books of Canonic Law, he didn't imagine that he would remove them and their effects from the world - he did it to mark his estrangement from Rome by a highly symbolic act.

So no, it's not analogous.

I think there's an assumption in there about the historical permanence of the written word.

Political book burnings weren't the only way the written word went away. Documents were unwritten for frugality too. Scraping ink off of parchment/vellum is easy. That's how you fix mistakes. That's also how you reuse parchment/vellum to keep from having to buy more (stuff's not cheap!). (Similarly, if you X-ray paintings, you'll sometimes find completely unrelated paintings underneath, because you're not going to throw away perfectly good canvas when you can just add another layer of paint instead.)

Imagine scraping and reusing parchment on which you'd received one letter to write another letter.

An interesting question indeed. For millennium years in advance all the current information will be priceless. It's just a matter of point of view, really. Surely some comments are worth deleting because of their uninformative nature. But for those in the future, it will be an artifact of the past days and the past culture.

There also appears to be a means by which unpopular comments can be down voted so much that they disappear. By this means perfectly adequate opinions can be made to disappear simply if they are unpopular. That doesn't appear to be right either.