A bit of a misnomer as obviously I am here but here you go anyway.
Unthought through offhand comments
I have just been subject to “comments” based on my age (as my screen name). I doubt the same would have been said if it was gender disablement or race but who knows. Was it funny, no not to me, but that’s the risk of the internet I guess. Luckily I am not easily offended.
General lack of courtesy (which I guess 1. Above fit s in as well)
Requests for features which include "I want, It should, etc etc. What should be said is “Would it be better if? Or How do others feel about”. No thought put into wording, or tone and that’s a shame. Feature requests should really be proposed if they will benefit a large proportion of users otherwise they really serve no purpose other than personal predilection and that is not a “feature”.
Anyway just my two cents, or maybe I am just getting grumpy in my old age :)