I fly a lot for work (I'm already at 67k miles flown for 2019 -- that's actual miles not airline miles (so that 67k is lower than my status miles)) and for anything over 6 hours or so, I fly business (unless I get an upgrade on a short-haul) and have had 6 flights over 10 hours this year, where I tend to have a lay flat bed and attempt to sleep. So I DO sleep on flights. Quite a bit (my flight to/from Australia was great, largely because I slept 9 of the 14 hours the first leg and 7 of the 13 hours the second).
I'd be just as freaked out if someone was recording me sleeping on an airplane in a ticket I paid $10k for as if I was when a hotel employee knocked once and then barged into my room in Sao Paulo back in December while I was changing into my pajamas. (And I was plenty mad at the WTC Sheraton for that!)