i feel like the point is that you have to take the uncertainty into consideration. you are gambling on what kind of bear or what kind of man and so the question is, which one, of unspecified danger, would you rather choose?
and so, since there is uncertainty baked in, it's basically demonstrating that women are, generally, more familiar or wary about the dangers of men than bears (there's a lot more one could say here, but this is basically the point i wanted to make)