Well, Peter, what makes you think that many scientists would make good entrepreneurs? Their record on Wall Street isn't looking so hot now. And how many scientists that you know would want to go into politics? Speaking for myself, I want no part of the business or political worlds. The hassles there, for me, are much worse than those of academe.

I agree that it is a good thing - it filters out the less committed. Basically, my view of being a scientist is that it is much like being a musician or clergyman - it's not a "career path", it's a calling. If you go in expecting to BE something (say, a tenured professor or a rock star), the odds are against you. But if you go in expecting to DO something (create new knowledge or entertain people), your chances for happiness are much higher.