10 people sign up. One has a work related emergency. Two of them decide not to even bother showing up, and give no explaination.
On Wednesday, when we're planning multiple heroic kills/attempts.
So 7 people don't get to raid because a few people don't have the manners to even show up, and pugging is completely out of the question. Swell!
THAT is why guilds have active benches.