If you go to cmas' thread you will see how, well, let's say 'picky' (actually anal) he is. His perfectionism (is that a real word?) transfers to real life and he feels everyone should strive to be their best.
He just wants people to do better that's all.
yes he can be a pain but that's just him, I know it sounds like I am defending him and maybe I am but once you get to know him you will, well likely not like him any better