Unless I come from an alternate universe - most people wear their seatbelt during take-off and landing and when the seatbelt light comes on.
I wear mine through most of the flight but I only started doing this fairly recently because I learned more about turbulence.
I'm not defending ignorance at all. I'm simply describing how poorly the risks are communicated and the reality that most people I've observed don't wear seatbelts for the entire duration of a flight unless the warning light comes on.