We spent hours and more hours on the raid when it was new, until we finally reached the point of being able to complete every encounter in 1st or 2nd try. When you get to that level you don't want to go back to the beginning of your raiding and spend 6 hours on the raid again. I'm no elitist prick, but that's the reality - I don't mind raiding with first timers, as long as they learn from their mistakes and listen to instructions. But when it comes to recruiting randoms through LFG to just clear a quick raid you really don't want that either, why would I want to spend more than 1 hour on something that I know I can do in 1 hour?