The only problem I truly have with damage meters, is that generally when you are in a group nobody cares about anything but top DPS, and won't hesitate to kick you if it is not up to their standards. And while normally I would have no problem with this, I mean hey if I want my own group that doesn't care about DPS nothings stopping me from making one, I do have one large irritant when it comes to damage meters....
The fact that people only look at the damage, period. Nobody cares that I stopped DPS'ing the boss for a minute to kill adds. CC. or save a healer from certain death because the tank failed to pick something up, they only care that for 1 minute I wasn't DPSing and thus was below their standards and /kick
This leads to tunnel vision DPSers who only care about pumping out as much damage as possible on a boss ignoring everything else in the environment, breaking CC's with AOE's etc, which causes wipes and frustration.
So while I understand people wanting DPS meters and personally use one in most MMORPG's to keep track of myself, I think overall they are generally a tool which actually lowers the game play standards of others when it allows you to measure and thus judge other peoples DPS.
/end rant