I have found that the mathoverflow community has become slightly more strict with time, downvoting and closing posts more aggressively if they are not in accordance to the general rules.
I guess that's because over time the number of messages have increased significantly (1 every 5 mns) and around half of them are not really about "research level" mathematics. As a result, people are quick to downvote messages that are not perfectly phrased or which are not 100% clear, in order to spend more time on the interesting questions. This of course favors questions from well-established users over casual/beginner users.
So you can say that the community has become more "collé-monté", and there are a lot of early questions a bit vague, broad or of a philosophical nature, [some][1]some of them gathering a lot of reputation, that would be discarded nowadays. I think that if you adhere strictly to the rules, you should see the negativity go away.
I didn't downvote any of your messages, and I hope you won't feel umconfortable if I make a comment on one of your questions entitled "Is there a Hotel California of set-theoretic geology?". The California Hotel reference can only cater to a specific geographic and demographic audience on mathoverflow. Keep in mind that the majority of the users here do not live in the US and unfortunately humor is a very cultural trait. Also I can't understand the body of the question, you don't give enough details. That's fine for me, don't modify anything, but that may explain the downvotes.
So yes, I agree, the community has become less friendly than in the early days. [1]: Fundamental Examples