First of all, the wheel chairs may be first on, but they are last off. Secondly, the chairs are queued separate so that Disney knows beforehand they have a wheel chair to load as they have to be loaded first for safety. Thirdly, when there are crowds at the end of the night to get to the bus, there are two or three busses that are able to pull in beside that bus, load, and be on their way before before the wheel chair bus gets finished loading the wheel chairs. Yes sometimes someone in a wheel chair gets lucky. But if the wheel chairs are 5 or 6 deep, well those at the back are waiting for possibly two wheel chair busses in front of them to load before they get their chair bus. That's 6-9 busses without wheel chair passengers that have loaded in the mean time when things are full up. And that isn't to mention the busses with the wheel chairs get to load a bunch of non wheel chair passengers too. Lastly, there's a way to avoid that mess altogether. Just buy an ice cream and sit down while the crowds clear a bit, then walk to the bus stop and spend very little time standing and waiting.