Preexisting Conditions?

I just saw this note, one that seems to make sense.

If health insurance companies are required to accept those with "preexisting conditions," who would buy health insurance? Wouldn't people just wait until they were hit with something, then go buy insurance (which by law would have to be sold to them)? They'd save all that money over the years, while there wouldn't be any more insurance companies since they'd go out of business.

Hmmmm....