People who say "this part of the song needs a lot of work" and give no examples of how it should sound. This wouldn't bug me if my tracks weren't my own creations which were made to suit my own personal tastes.
You can't tell a painter his painting is bad then provide no examples of why it is bad outside of your own personal preference. Granted, good and bad are both entirely subjective, so to offer any kind of criticism would be judging based on your own personal preferences... where was I going with this?
Fuck it. Cake party!