Sometimes you feel like a punch, some times you choke. They are positive they will come out on top of any situation even without planning for it in advance. Earthquake, Fire, Flood, you name it. What is almost positive, however, is that they are in for a big and unpleasant surprise if they should ever tangle with a skilled grappler. Natural disasters don't happen that often to us and they don't strangle you, break your joints, or dump you on your head on purpose.
Aggressive grapplers do.
They resign themselves to more powerful forces at work, whose will they cannot deny. If I get hit by a truck or stuck by lightning, it's my destiny. This one is weird to me, but there are people who actually enjoy being subjected to large doses of pain. I guess that's one good reason not to grapple. Just let the other guy use your body as a grappling dummy.