The key thing about things like Twitter and, especially, Facebook that makes them get such hate, I think, is that as a user, you are their product -- not their

The key thing about things like Twitter and, especially, Facebook that makes them get such hate, I think, is that as a user, you are their product -- not their customer. They don't get money from you, so their interests are not aligned with yours. This leads to a lot of perverse behaviour in the interests of extracting value from your use of their site. This is in contrast with other services (like Github, which someone mentioned), whose interests are aligned with yours. They want your experience to be good so that you continue to give them money.