The biggest issue is that people are too quick to just agree and give up the second something goes wrong.

About a week or so ago, I joined a CT group in progress at the Bone Dragon. By the time left, there couldn't have been more than 1 wipe, but 3 tanks were missing.
One of the guys suggested we try it anyway as 3 tanks should be enough. Someone disagreed, and then a 3rd person backed up the first.
The second guy dropped.
Without a work, 3 more people dropped 5 seconds later.
Then one by one, everyone just dropped silently until I was the last person in the raid...

Seriously... The whole, "We'll have to wait for replacements... Might as well re-queue!" mentality there is terrible. >_>
Replacements came in and we got a full alliance up much faster than if I'd had to requeue (was at ~28 minutes for a JiP and well over 6Ø for a fresh instance).
Vote abandon wasn't in at the time, but I'd have been annoyed if it were since I'd have gotten the boot even if I said no... Then back to the ridiculous queue...