I still don't agree.
The problem with DPS meters isn't that damage isn't important, it's this:

Average Damage done per second across an entire boss encounter is almost never relevant.

Except for the very simplest fights - Patchwerk for example - the key to the fight is overcoming the mechanics.
It's not about doing X Damage every second, it's about killing the whelps during Phase 2, or killing the portal, or avoiding the fire etc.

So yes it's about damage, but it's also about doing the damage in the right place at the right time, and DPS meters don't tell you that, or - more correctly - some do, but people don't link that.

If you're doing low damage on a simple fight you're doing badly.
But if you're doing low damage on a complicated fight, a DPS meter won't tell your if you're doing well or not.

@Tom In Yvl's specific case, it did work in pointing out the player who wasn't following instructions ... He/She didn't say that DPS meters are awesome nor that they are the most important thing or that they always work in every situation as a "You are playing badly!

So your answer, while true, I think was a little misplaced ;)

Damage meters have their place, but very rarely as a tool to show your damage.

How much damage you're doing can be meaningless if the damage you're doing is limited by your spec and gear. If they're getting the best out of their situation, but other players are doing better, it's not really fair to say "you're doing crap DPS, /kick".

I, for example, am very often 3-4th on damage in our raids, usually by a percent or two, but sometimes significantly more. My RL loves having me around. Why? He looks at the interrupts, dispel and damage taken aspect of the meters and nots that the reason my DPS is lacking is because I /stopcasting a lot more than other casters.

I make life easier on my healers and tanks. As long as we're all above a threshold, DPS is fine.