I'd suggest: at the point where you start paying for the "sharing" in money.

I have much more respect for something that an actual person owns. If it's some mom and pop bed and breakfast I respect it a lot more than if it is some hotel.

EDIT: After thinking some more it is all boils down to how much the owner cares about it. For example I really care a lot about my car but the rental comapany doesn't really care much about any specific car that they own.

When's it's owned by a publicly traded company.

I guess I should clarify: I put in extra effort to treat them nicer than baseline.