- Garrisons were badly executed. Could've made it instanced for all people who had a similar setup with buildings or something.
- Promises they did not keep. I was personally incredibly excited about the Temple of the Karabor.
- The story was horrific. Go to a different time, save Draenor from big bad guys we all knew from lore, let Green Jesus kill of the previous big bad guy (seriously, enough with giving NPC's the honor) and changing the end-content cause: "Why the hell not?".
- Giving everybody everything with minimal effort which made it very exciting the first 2 weeks and then realizing that there is no point in continuing cause you got good stuff anyway.
- The playerbase. Used to be that you could join a pug easily and if you weren't good enough you'd leave. Now its simply a matter of "Link achievement" and you're in, but you can't get the achievement without getting in >_>
Basically: Too many broken promises, the feeling of progression is missing, lack of (quality) content.