I can totally relate. I'm among the top (if not THE top) DPS in my guild. For the last 3-4 months, I've participated in our 25-man Naxx runs ONLY to fill a slot so other people can get gear. And I did this with the impression that the faster they geared up, the faster they would participate in progression raids.

Except, our progression raids are primarily 10-man and scheduled on Tue-Thur, and these members I'm helping simply don't sign up, partially due to unavailability and partially due to feeling they won't get in the raid anyway. After officers, there's usually only about 2-3 slots left for others in a 10-man. At the start of Ulduar, we had tried to run two 10-mans, but people either still wouldn't sign up or resented being on the "B-team," even with the GM trying to make the teams as even in skill as possible.

We're currently back to running 2 10s, but I feel the damage has already been done with us looking to not down Yogg at all until after 3.2. . .Morale's pretty low.

Getting back to relating: A couple of weeks ago, I choose not to sign for the weekend's scheduled 25-man Naxx or Ulduar. At that point, I'd been working 10-hour shifts for 6 of the previous 8 weeks, as well as missed a lot of sleep having appointments to make some mornings out of town. My GM asked about me not signing, surprised I didn't want to even do the Ulduar. I told her I was feeling wiped and needed a break; she already knew the details. I also told her how weary I was getting of running 25s with so many pick-ups. She said okay, but then felt the need to remind me that the pick-ups were a necessary evil to do 25s and that every guild member that doesn't show up just sets us back from having full guild runs. . .

. . .I almost came undone. I'd been filling slots simply for the sake of filling a slot for months on end, and the one weekend I choose not to, she throws that at me. It's like "Yeah, I know. . .why do you think I've been signing up for the last several months?!"