Not OP, but it's just general discontent with the site.

Some people are really unhappy about the policies and changes that the site has made in the past year or so. A CEO that is kind of out of touch with the community. The banning of a couple places that a lot of people liked, despite their questionable goals. The restructuring that left a lot of people without a means of doing their job. Some people are leaving, because the site is going down a path that they really don't like.

Others are leaving, because they are tired of the community. They're tired of the hive-mind attitude. They're tired of the constant pun threads and contests to see who can come up with the funniest, mildly-clever comment. They're tired of how childish the community gets when something they don't love happens. They're tired of everything being so political and super serious. They just want a place where they can just talk and discuss things, without it devolving into an absolute mess.

If you ask people in general, they'll tell you how Ellen Pao is the spawn of Satan, and is running the site into the ground. They'll give you specifics about how /r/fatpeoplehate was banned and how it was unjust. They'll tell you about the firing of Victoria, and how that affected the process of doing AMAs.

They'll explain how everyone is so willing to jump to conclusions, without facts. They'll tell you about the countless "woah I did Nazi that one coming!" threads, and how low effort they are. They'll tell you about all the Gamer Gate and Feminazi and SJW posts, and how they dominate every discussion. They'll tell you about the temper tantrums that people throw about every change to every single detail they don't like.

However, they're all here for the same reason: they don't like the current state of Reddit.