The point of the roulette is so that people that have completed the content can go and be assigned with people that haven't completed the content and help them through. Going through a dungeon quickly is all well and good, but speed runs are insane! I find that a failed attempt to speed run takes longer than a well paced run to clear because a failure to speed run is death and then there's all the travel time to get back to where you were and if you keep trying the same thing over and over and the DPS, heals OR tank is not well geared or able to handle the number of monsters it'll all end back the same.

I try and bear with suicidal tanks, but really... there's a limit to patience.