Honestly I see this pop up as a topic from time to time but on Couerl I've NEVER seen this happen in my roulettes. I always go in as scholar (sue me I'm lazy after the 1000th dungeon and for dungeons scholar is 2 buttons -_-)

I've never seen anyone complain about speed running if it happens. Only time I've seen it NOT happen is if either the tank is THAT badly geared (very rare) or one of the dps is a monk (even more rare.. People seem to have figured out that doing roulettes it's best to play bard or blm). And in both of those cases I've never seen anyone complain that we weren't training because of group makeup making it inefficient/impossible.