Garrisons drove me off. Yeah, there was the ranch with Pandaria, but it didn't tie into the essentiality of your character. With garrisons, the game felt like Farmville. I had 11 toons, so that's a garrison for each of them. With Legion I was like "twelfth character? nope!" I just wish the class system could be more like FF14's: one character can be every class, but class switching is of course disabled for dungeons/PVP or given a penalty. FF14 is not casual friendly though. Leveling a character in that game requires you to do dungeons and stuff. Imagine it like BC raid attunement, but instead of attuning for raids, it's simply being able to unlock game features and hero classes.
Actually, better yet, imagine it like if you wanted a demon hunter, you had to timewalk every raid from MC40 all the way to Draenor's citadel raid before you could play one.