Almost everyone answer has been removed by the mods. Just like this question will be. I could understand removing a comment or two if they were inappropriate but deleting all answers seems like censorship. So why are the mods so afraid of free discussion?
On /r/AskHistorians, the idea is that people asking questions get answers that have the expertise you'd expect from a proper historian - thus the name of the subreddit. We'd rather have no answer than a thread cluttered with bad answers, jokes, and people saying "where are all the comments?". By removing the short, quick, bad answers that would otherwise crowd them out, the well-researched in-depth answers (that take people time to research and write) are more likely to be seen (see this graph for more detail). If you want to see what a pretty typical bunch of removed comments looks like, here's one we screenshotted earlier.
This heavy moderation works: we have found that it takes an average of 9 hours for a good answer to appear on a popular thread - properly researching and writing an answer takes time - and that 90%+ of popular threads get an answer. The last time we did a survey, 75% of /r/AskHistorians subscribers approved of our moderation, while another 5% thought we should be stricter (and 15% said they didn't care).
We want people answering questions to be able to explain not just what the basic facts are according to academic research, but why we know that these basic facts are right, and to put those basic facts into context. This is why we encourage the use of primary and secondary sources in answering questions, rather than tertiary sources like Wikipedia, podcasts and textbooks. Unfortunately, the downside of encouraging in-depth and comprehensive answers is that we have to remove a lot of shitposts and comments wondering what happened to the removed shitposts. The upside, however, is that our contributors consistently post amazing stuff to /r/AskHistorians (which we collate the best of every week in our Sunday Digest), and daily on our Twitter. Alternatively, if you want to discuss history without these constraints, /r/history or /r/askhistory might be more appropriate subreddits for you than /r/AskHistorians.
You have a fundamental misunderstanding of this subreddit, evidenced even by the fact that you think this question will be removed. We only remove META threads if they are phrased in a way that is unnecessarily rude, under the civility rule (i.e. "Why the fuck do you pieces of shit remove all the fucking questions!?"). If what you are looking for is discussion, you simply are in the wrong subreddit. /r/History is the main general history subreddit on the site, and that is where discussions happen. In this subreddit, discussions are limited to the a few of the daily Automod threads that get posted - especially the Monday Methods on whatever the current topic there is, and the Thursday Reading and Research which can be on, well, whatever topic someone brings up to chat on if it can be construed to relate to that broad theme.
But for the questions asked in the sub, what we offer is a curated experience that admittedly isn't for everyone. And that is fine! We aren't trying to make a subreddit for everyone. We're trying to make one for people who want that experience, and we do a pretty good job at it. Yes, you have a better chance of getting a answer in /r/History or /r/AskHistory, the later being sort of the "in-between" that focuses on the Q+A format but without the strict ruleset, but if you are looking for quality over quantity, then /r/AskHistorians blows them out of the water. But maintaining that level of quality requires strict rules, and stern enforcement of them. And it does mean fewer questions get a answer, but it means the ones that do get a good answer.
That isn't censorship, which is an entirely different topic, and would be a discussion of whether we are removing answers specifically because we disagree with them personally even though they nevertheless reflect an actual position supported in the academy by current scholarship, and conform to all the stated rules (Answer: We don't mod in that way). That is curation, and enforcement of standards. There are rules publicly posted, and we enforce them as written. If that isn't what you're looking for, then maybe this subreddit isn't for you.
Rules 4, 5 and 6 exist for a reason.
If you went out and bought a book to learn about the Battle of Stalingrad and it was 200 pages of Nazi puns and quotes from the script of Enemy at the Gates before 2 lines at the end saying "Russians fought Germans in a city and loads died and it was awful", you'd think it was a pretty terrible book and not worth reading.
If you demanded a refund, should we accuse you of censoring the free discussion?
Usually it's for violating rules 4 and 5 in the sidebar. As the mods keep having to remind people about over and over and over and over.