Just as evidence that people are in fact still interested in running it...

About a week ago one of my FCmates who had just hit 50 unlocked CT, so we decided to put together a server-wide alliance via PF so that she could experience all three raids. We had 24 people ready to go in approximately 20 minutes, all of whom stuck around for all three raids. The general attitude was that people were very happy that someone had organized a group because they missed running it/wanted a piece for glamour/wanted to do the weekly to upgrade their IW stuff or to get an IW weapon. So why didn't they just queue up for it on their own? Because the queues were prohibitively long.

Lengthy queues can dissuade people who might otherwise run something. If someone only has, say, two hours a day to play, and their choice is running a few dailies or spending the majority of those two hours queued up for a single duty, most people are going to choose to do several things instead of sitting around waiting for just one. Want has nothing to do with it when you factor in the fact that the majority of players have a limited amount of time to spend on the game daily.