I'm leveling an alt priest (disc for healing) and would not be doing it without the dungeon finder. I love it and my general experience has been extremely good. With that being said, as I have entered Outland, I have noticed an increase in really bad players. I'm not sure why, to be honest. I would have thought this would have been a problem in the lower instances, but maybe it is simply more noticeable as the instances become slightly more difficult and bad play becomes more obvious.
A few examples:
Yesterday afternoon in Blood Furnace, a Warlock in our group was using his Voidwalker, which offers absolutely no utility to the group. I whispered him and suggested he use a different demon to boost damage and/or group stats. He ignored me.
In the same group, I advised the tank to pull mobs away from the mines as they do massive damage and can easily lead to a wipe when pulling 2 groups at a time. The tank ignored me and the group wiped. I left the group.
On the final boss in Ramps, we wiped (never should wipe in Ramps) because the entire group stood in fire. 2 people typed in party chat "WHERE WERE THE HEALS" and I explained that I can't heal 4 people standing in fire. We started again (after a 15 minute delay b/c people don't know how to find the instance) and they did the same thing again. I dropped.
So, here is my question, do you even try to give advice in random 5 mans? If so, do people ever listen? It seems to me that you can get a sense of a group pretty quick, and, if it is bad, don't waste the time, just drop, quest for a while and wait for the cooldown to be over and join the next group. Just curious what others do.