If somebody is new, he gets precedence over the majority. He has the right to experience his first run calmly and explore everything. As for the rest, I never oppose doing something extra. I like most Dungeons and I am in no hurry to finish them, and even if I happened to get one that I don't like in Roulette, the difference is 5-10 minutes at most. It's not like I'd be doing anything important anyway, I'd still be playing the game, so... it costs me nothing and makes a person happy; I see no reasons to oppose.

The only thing I don't compromise on are speed runs. I hate them and they completely ruin the game for me to the point it's not fun anymore, so if if the rest of the party wants to SR even after I said no, I simply leave (but no ragequits or insults thrown around of course).