Of course you certainly learn a lot by starting a company, it's a matter of making sure you are choosing that over college for the right reasons, and not 'only' because you feel like you will be the next twitter in a year, which most likely won't happen.
I think that there might be a more natural order in going to school first, then starting a business. But it's not necessarily the unique or the right way. It's what I think.
Ultimately it depends on the person. It's just hard to judge well about college when you haven't really gone through college, and I think that starting too early could be worse than starting a couple of years later. Just my opinion.
It's not like there won't be any opportunities after college. So I just feel that I would expect a strong reason to feel like I can't wait anymore. But if the reason is that one thinks that in college you don't learn anything but working for someone, then I think that's the wrong reason. That's all.