I am an American and I hope I am not the only dissenter. I don't mind plastic things you insert in a slot so that the A/c or heat is turned off when I am gone..
It doesn't take long to be comfortable once the A/C is on. It's almost always cooler in the room than outside. I consider it a terrible wwaste to have A/C running when I am going to be gone.
A/C or heat turning itself off when you go to sleep would be annoying though.
It shouldn't be difficult to design a thermostat override the motion detector so that the a/c kicks in when ambient air rises above a certain temp. Keeping the blower on would help too.
Sometimes when I walk into a room in SEA (South East Asia), I wish it wasn't so hot. What annoys me more is walking out of an air-conditioned room into hallway which is hot. I know I will be hot ans=d sweaty when I step out of the hotel, but I would prefer not to go through the change every time I step out of the room.
If I can manage without A/C, I do. I have taken rooms without A/C a a couple of times.
On one trip to Cambodia, I had to turn the a/c off in Battambang as the air was too dry and it made it impossible for me to use my CPAP. I did not take my humidifier in order to pack light. Cold dry air rushing through my nostrils kept me awake. Room without a/c was cheaper (by a few dollars ). They turned my a/c off and reduced the charge from $15 to $12.
In Phnompenh, I took a room without A/C, $7 versus $10. Not a big savings for me, but it is in Cambodia as electricity is very expensive for them. In some parts of Cambodia, hotels generate their own power. No A/c meant no hot water too. But I found showering in unheated water to be very refreshing. Not cold, not hot. I rarely like very hot water for my showers.
In summertime, the hot water faucet is turned on to barely a trickle to take the chill out of the water.
I hope there are more people like me.

I think bypassing motion detector when you go to sleep is OK. One should be able to sleep in comfort. After all two main purposes of a hotel room are sleeping and washing up. But major tampering with the thermostat is bad.