The thing about getting some work experience before you go to school is that it may make you a better student. You'll have a better idea of what you want to learn and why. You'll be better equipped to recruit future colleagues from among your fellow students, and you'll have better war stories to tell them when you're sitting at the bar.
The idea that "a degree is a nice thing to fall back on" is true, but the reverse is even more true: If your career falters, you can always go to college. (If you have the money, of course... but if you won't have the money then, you probably don't have the money now either!)
But, seriously: I agree that the college experience may be most enjoyable when you're in your twenties, if only because that's how old most of the other students are. You may not want to be so old that you feel a generation gap with your own classmates. But the guy is nineteen. He's got eleven years to go before he's thirty. He can afford to work at three or four startups and still graduate from college before he's thirty.