I have no idea really, but maybe one is to save on electricity. One Travelodge we stayed in, we were watching TV in bed and each time one of us moved, or turned over, the TV switched itself off! It was really spooky.
Not seen that, but they do seem to be big on saving electricity (the UK one that is). I'm not sure if they'd change the blankets for example if you stayed more than 1 night either.
The TV thing was probably a lose wire if it was the US version going by the one I stayed in. Luckily the UK version seems a little more reliable.