My take on this is we are dealing with opposing goals. The property is trying to reduce costs and, in some cases, the staff is trying to maximize pay. There are some properties that pay on a piecemeal basis. So if the staff is going to make more by cleaning more rooms, guess what... DND will not stand. A tactic that I've adopted is that I'm gonna get disturbed, but when I answer the door I tell them I do not need anything and go ahead and mark me as cleaned. That gets me off their list for the rest of the day. If there is an issue with getting points, I deal with the front desk at check out.