Completely closed GM who won't take any criticism for an answer, even on something that is a blatant logical fallacy.

Sitting for a week or more (people justify it with work and slow schedules; I disagree when plenty of folks come online with an opportunity to do something and when other roleplays move at a faster pace).

A boss without depth. I am of the mind that there can be "big bads" that do quite well, even though they can wipe out characters in one swoop potentially, by developing them and allowing for holes. That doesn't happen when you have characters that are simply OP at everything with no drawbacks and really have no reason to continue letting heros do anything for any other purpose than amusement. That changes the entire course of it; a chance to fight back and possibly defeat the bad guy vs. an obvious throw-in OP. I draw on one time in particular when I saw a roleplay (offsite) that was stat based with the boss having 20x maximum player health limit, tons of regeneration, super fast attacks, one hit kills NO MATTER WHAT, and no backstory, or even a real name. Needless to say how fast that crashed. I didn't even need to criticize it considering everyone else in that thread was doing it for me.

Inconsistent postings that are unregulated. If there is a system to posting, alright. If it is spouts of extreme activity where others don't even get to blink and half the roleplay is done right in the course of two people and an hour... that's not good. Folks ought to wait for some reaction and interaction before doing another post. Sometimes I have opportunities to reply in posting strings; but considering I often don't have the time allotted to post except for every evening, I try to show the same respect lots of roleplayers have shown to me when it comes to not advancing a plot too far and leaving folks into the dust.

Probably other things and this could use a little proofing, but typing this makes me realize I have another roleplay I need to start on 5 minutes ago.