Maybe 1 in 20 PUGs will I come across someone I don't want to group with again, and it's always because they had an attitude problem or did something like queue up as tank when they are DPS spec/geared. Most runs are smooth, and disbanding because we can't beat a boss is exceptionally rare.
Yet I frequently hear people say they've sworn off PUGs or they hate them or whatever.
I see a number of possible explanations:
People like to complain/act superior
Bad players who do not know they are bad complain that groups are bad (unlikely that this is a main factor, I think)
People get upset really easily/I'm really easygoing
Or it could be that I'm an awesome healer who makes up for bads. Of course this is my favorite theory, but I am biased, so I want to find out what other people have experienced and think.
some of the major problems are a few peoples' expectations are too high for players new to mmos, have little patience with them and are not capable of teaching them. they expect everyone to know how to play rather than try to teach them. most even lack the tact in dealing with such players and instead just leave the group or rant on and on. most new players want to learn and are willing to listen. these are not the problem players i have run into though.
yes i have run into some poor players in pugs in here but have done so across every mmo i have played. most of these players are well geared and are guilded. this is the problem. they think they are better than what they are because they came from a different mmo trying to use the same tactics when this games mechanics are different. you cant tell them anything. they are the problem and not the newbs nor f2p players.