Gevlon is turning into a real social type of player these days, on a crusade to improve the level of play in instances. Whatever happened to goblinish profit-above-all motives?
Still, I can't help but think his methods are backfiring. Attempting to kick the lowest DPS resulted in the group kicking him instead. To be honest, that exchange was probably the funniest thing I've seen all week.
People generally aren't going to kick someone for underperforming, so long as the performance does not affect success. If success is a bit slower than it could be, that's okay for most people. However, causing the group to wipe--as Gevlon did--will get you kicked.
In my experience, people are very lenient about trying. As long as the player is not just /afk leaching, people are tolerant of performance, regardless of how good they are actually doing. It's only when wipes happen, where the lower performance results in actual failure, that the tolerance disappears.
I think the carrot might be a better weapon than the stick, at least in random PuGs. Post the meters, say that X could do better, and then point her to Elitist Jerks. That probably will have a better success rate than attempting to play power games, even if you are the healer or the tank.