Well, you have people flying aerobatics for fun, which provide much greater negative G forces than quite extreme turbulence. It's just a matter of personal preference; turbulence is completely harmless if you're strapped in reasonably tight :)
I'm actually one of those people who (occasionally) flies aerobatics for fun. It's a lot more fun if you can see out the front, which you typically can't in a commercial airliner.
