We've had a knock or two, but its never been aggressive. I seem to be incapable of sleeping in at Disney, so there is a soft knock and "housekeeping" and I say "we are still here - we are planning on being out at X:XX." Then I don't hear anything again.
Technology and customer service could help fix it - they could ask you to scan your magic bands at a check out station in the lobby when you are out of the room - and get a $10 room credit applied to your Disney bill. The housekeepers probably work with tablets that check in rooms when they are clean and let them know which ones are on schedule - they'd know which rooms are unoccupied. But we'd end up paying for that $10 in our dues.
They could also make housekeeping a much less desirable job by having five hour shifts for the bulk of the housekeepers - starting at 11:00 and ending at 4:00pm - and having more housekeepers. But my guess is there isn't a glut of people who want a part time job that doesn't pay well and involves cleaning up after entitled privileged people (no one here, of course

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