That's because waking someone who refuses to be woken up is a pain in the ass.
Typing this as I'm trying to get my sister's ass out of bed.
Sooner or later you get an urge to just give up and let the person take the consequences of not waking up, because you don't want to waste your precious time and energy trying to help someone who doesn't want to be helped, as they grunt annoyingly at you making you feel bad for trying to help them >.>