Anyone who thinks that the main reason PUGers are not invited into raids is greed over loot, is missing the point. When you design a raid so that you have to spend 1 or 2 hours just getting to it, then if one person makes a simple mistake it is all over for everyone... Well you get the point...
Who in their right mind would invite unknown randomness into that kind of situation? If you want more people invited into raids, make the penalty for individual error substantially less.