I know that the shop has had to make repairs on broken tips; and over the years there have been sightings of basses with broken tips on Ebay. So it can happen; and my guess is that those unfortunate owners never thought it would.
Accidents do happen, and of course trying to do everything you can to avoid accidents can at times become untenable; for instance, you might never drive an automobile in city traffic if you wish to avoid all risk. So it's a matter of choosing how much risk you are comfortable with. For me, I can't see me putting my bass in a gig bag. But then there are lots of thing I wouldn't do that others do without hesitation, and there are things that I do that others wouldn't.