To throw my own 2 cents in here.
I think a lot of the issue with the Beta in particular is most people have gotten used to what I like to call "Fake Betas". Betas that are basically the full game and their only real purpose is to stress test servers at most, and generate hype at the least.
This Beta feels like an actual Beta to me. It has bugs, it has server issues, it has missing features. Its not just a glorified demo version of the game. And personally, I find it actually kind of fun to try and break the game, discover bugs, try to guess whats causing it, and watch as the game evolves as the developers fix issues. But I can see where others who are not like me can be frustrated, but them being frustrated is kind of the point of this Beta. (So they can be less frustrated when the game releases)
In addition, part of the issue may be that the Beta access was not free (boy, could you imagine how terrible the servers could have been at first if it was!?). I get that people want to feel that they are getting their monies worth, but this is what they signed up for.
At the end of the day, there's a way to give feedback and criticism without being a jerk about it. The best way to deal with those kinds of negative posts is to ignore them. Responding only rewards and reinforces the bad behavior. Only reward good/positive/constructive behavior with a response, not bad/negative/meaniehead behavior.
Love this! Also believe it's very true. I was telling a friend, who is massively into video games, about the Beta recently and his response was that the beta should be the finished game with only minor bugs and stress testing. I haven't done a beta before, only 1 early access experience, but my understanding was that betas are there for testers to hopefully help work out a lot of issues so the finished version is a great game.