[jajko]

Its expected that crew will light seat belt signs when they asses its required. Its literal on/off or yes/no, lets not add some 3rd state to it that will confuse people.

This of course doesn't mean one shouldn't wear it as often as possible, but ie with small kids thats nigh impossible, or for some folks on 10 hour flights (I still used to put it on me when I slept, but mainly to not be woken up by crew when they switch it on and check everybody).

Very similar topic is bus seat belts. All intercity buses (at least in Europe) have them, nobody clips in (apart from driver). I think at this point everybody knows about some horrible bus tragedy which would be a set of minor scratches if all folks had seat belts on. Yet our subconsciousness keeps changing perceived risks and consequences to keep us happy/content instead of worried about everything all the time (makes some sense, cluttered mind ain't best performing in life & death scenarios of bygone era).