Not to be insulting or anything but remember EVERYTHING is a matter of perspective. People can be hypocritical, and I am desperately trying to find the most thoughtful and polite way to phrase, but you are doing exactly what you said you didn't like people doing. i.e. complaining about GW, nerfs, whatever. Everybody does it, I certainly do it a lot, and more importantly it means you are invested in the game, which is a good thing, so just remember that something that may seem annoying, rude, or caustic, may not be intended as so, and might be influenced by your perspective. Not trying to call you out or anything, just keep perspective in mind
I'm not gonna lie, as a relatively young-ish member of this community, I have also found other various communities which are quite toxic, and if anything this hobby, even the competitive side, is the healthiest community i have ever seen, both in a broad snese of wargaming and Warhammer, as well as more narrow like TGA. I like participating in these communities because its so different than others I am used to, who will not help, hinder, and insult you at every opportunity, which leads me to the end of this long and winding road, remember to get some thick skin when you on the internet or just interacting with people. A lot of the time they don't mean what they said, I oftentimes sound caustic and long winded, but usually I am not trying to be. So just try to ignore some of their negative qualities and focus on the positives. Speaking from a younger standpoint, I never got into the hobby a few years ago since most people in my local area and playing were years older than me, and I remember it was intimidating, and honestly a lot of the time I was very isolated from the rest, so if that is happening to you (I am not saying it is) than just try to stay in it, it can be intimidating, but after a while you can manage to catch up and participate in their jokes and clique. This ends my rant, in summary remember to have thick skin on and off the internet, as well as not to be intimidated by age or just being a different type of people (idk how best to say it).