Very true, but they have the park pass system now to assist with that.I think the problem with that logic is that you are looking at the utility of fast pass from the standpoint of the individual guest (which is of course a totally reasonable thing for an individual guest to do), but WDW looks at it from the standpoint of global park operations.
I have a hard time seeing that ever disappearing. I know guests hate it, but WDW LOVES it. Gives them all the control in the world.