Which is why the wire clamps should probably be packaged with the fixture. I’m guessing the reason most people don’t use them is because they don’t know they need them and don’t want to make a second run to the store. That’s the reason I skipped it when I put a new vent fan in my bathroom. Ended up putting one in a few years later when I had to take the fan down to get access in the ceiling, but the wiring looked fine.