I didn't leave, as much as I stopped going to the actual message board part, as the moderation became very heavy handed, and the message boards were unironically the best part of the site when you're not reading the guides. The problem being, I wanted to talk to other people about videogames and it became much harder to do so, on top of the userbase becoming more... ... ... I don't have the proper word, but their mindset became consolidated, and I'm not talking about political views. But let's say you had a question about something and you go to the forums; you risk running into one of two answers, the first being CHECK THE FAQ, which isn't entirely a wrong answer, especially if you know it's in one of them. But the other answer would be people discussing everything around the exact answer you're seeking; they most likely know the answer, but what they give is an exercise in self-satisfactory fart-huffing about how smart they are and talking about the question, without giving you an answer. And I enjoy they implemented the Questions part, which is where I mostly go anymore; but you still get the same fucking problem there as you do on the boards. Fart-huffing retards giving a non-answer.
Edit: And I don't know where or when it started, but this is one of my biggest complaints about "the gaming community" as a whole. There's a sense of retarded elitism that exists when there doesn't need to be. Whether it's Elitist Jerks, Icy Veins, or whoever, there are weirdos out there who crunch numbers and determine the optimal path/gear/build/etc. And I'm not here to say they or anyone else is wrong; but the amount of blind deference and inability to experiment or fuck around is damaging.