Agreed. But I'll just add one option that worked for me. I dropped out after the first semester. Then I found a job as a software engineer. In 4 years I'm a valuable senior java developer that everyone is trying to hire. Have I graduated? Yes, from the school of real-world software projects. I didn't have a startup business (well, I had one which failed, and I'm having one right now, on the side), but it was still a better option to drop out.
Btw, I signed up for a external program at the University of London so that I could still get a BSc without actually doing anything academic - so now I'm 24 with 4 years of real-life work experience and a BSc (not that I need it, but it's there)
So, perhaps it is better to summarize it that way: if you clearly see opportunities for yourself that are better than staying in university - drop out.