If they are that precise about getting everyone out of their rooms at 11:00am, they should have absolutely no problem making sure rooms are ready for a 4:00om check-in.
Depends upon how cooperative the guests are. There was a huge thread about this a few months back but IIRC there is very little the resorts can do to evict people who stay beyond the posted time. Even if a guest leaves his stuff in the room and heads to the parks, they cannot simply lock the doors and remove luggage. And there are further complications if the guest is physically in the room and refuses to leave.
What they CAN do is start charging additional fees to individuals who do not leave promptly. That would at least serve as a deterrent.
I can understand them being a little lax on the hotel side because Disney doesn't want to remove all traces of being guest-friendly. But I do think the DVC side of the business could benefit from some stricter penalties associated with late departures. Seems like a no-harm, no-foul policy if members are adhering to the guidelines to begin with.
If we are supposed to check out at 11:00 then that means 11:00. I mean I guess in an extreme situation of some sort ( I mean extreme too)......maybe the guest requests an extra hour, but then I could see that being abused too. I just think people need to follow the dang rules. Disney included......they should compensate guests whose rooms are not ready on time. Then maybe they will see how many rooms are REALLY not ready when they see how many guests are being compensated with gift cards or what have you...... and start hiring more people to clean them in a timely manner.
I'd clean up anyways, but I always make sure there isn't a spot left on anything in the kitchen when we leave for fear of being charged.

