I was in a Copperbell run where the tank pulled everything up to the first boss. Sadly, he died, then I did (as a DPS) and I got no XP whatsoever when he and his friends killed all the mobs.

So yes, I'm against that sort of pulling in levelling dungeons because you may end up screwing over people who are using those dungeons to, gee I don't know, levelling maybe.

If you sign up for a levelling roulette knowing you MAY get a low level dungeon and you don't want to run it at a slower pace (2-3 packs per pull), then form a pre-made and spare the rest of us the frustration of waiting 40 minutes in the queue only to be screwed out of XP because the tank was a... jerk.