Leveling roulette really should be leveling and not rush through the dungeon just to get a bonus. I'm leveling jobs in Brayflox now and of course, no one wants to kill everything. They just rush through the dungeon to get their bonus while I lose out on 10,000s of exp. Even worse in Aurum Vale because no one wants to let the fruits spawn (and the seedlings are ridiculously easy to kill). What sucks is if it's a DPS role, I have to wait 20-30 minutes to just to lose out on a crap ton of exp.
I would like to suggest that leveling roulette have an additional bonus, a very substantial bonus, that makes it worth people's time to do a full clear. Maybe double the tomestones or gil or something, so if someone asks for a full clear, people won't just tell you to fuck off and rush through it.
If not, then make a separate leveling roulette that gives extra XP per mob, or barriers that won't come down until an area's cleared.