I agree. Saying that I have a lot of dungeon achievements or gear level whatever just means I've been lucky on rolls and groups that could drag me through. It tell you nothing about my actual skill.
My point of reference (and example) is this: I ran two random heroic pugs using the new LFG tool. In the first isntance, I was the lowest DPS - I was less than half of the next closest person.... the tank. They were all uber-geared, and mobs were dying so fast that I couldn't wind up my DPS in my arcane spec. And I wasn't slacking - I had used a flask and food to try to maximize my DPS. Long and short, they didn't need me. They could have EASILY 4-manned the instance. I saw no gear drops here. Had there been anything for me, I could have AFKd thru everything and still won a huge piece of gear, gotten achievements galore...and got a shinier score on the mods.
I was a little bummed about my performance, but decided to do another one. I was the top DPS, and the 2nd guy was less than half of what I did. We still breezed through the instance, but I still saw no gear drops. I didn't get any unlocks because we played it safe and killed all the adds on the boss fights, didn't break any speed records doing it, etc. My gear score and achievement score were unchanged, yet it wasn't at a lack of effort or ability on my part.
Would it be fair to kick me from a group based on my gear score of 2006? Or the fact that I didn't blow 2k to gem gear that I plan on replacing as soon as I get the badges built up? Because I know that for every person like Rob that will just take it slower, there are 3 PUG people that just don't want to mess with me and would vote me out of the group.