I have been tanking since 1999 in EQ1, love it, and will never roll a DPS for more than the occasional *****s and giggles.
My wife plays a healer in all the games we play so it works out pretty well.
As far as stupid DPS'ers, we just put them on ignore, and boot them from the group. Once they are on ignore you will never be put into another random with them, lovely system.
Generally we give them 2-3 chances .. everyone makes mistakes afterall. After the 2nd or 3rd time I will usually stop the group and address the problem, if they respond positivitly they can stay, if they start throwing out insults and playing the blame game, away they go!
After a few weeks of PUG'ing your ignore list will grow quite a bit, but you will slowly start weeding out the idiots.