Dropped ex roulette yesterday (Fractual Continuum) due to a tank, ilvl 185ish, pulling as small as possible. I found out for the first time that there are individual enemies that can be pulled on the way to the first boss O.o. We said polietely that he can pull more mobs, i can heal through it, and the BRD and BLM were more than capable of killing things fast, but nope. Response we got was the tank was in no hurry......took us 12+ mins to get to the first boss since he kept pausing after we killed things as well.

So having people deliberately waste others time and slow the run down i suppose is what makes me drop a group.