I started a hosted email company in high-school, and while it never really went anywhere, it was the single greatest thing on my resume.
It made me stand far above most other applicants, proved that I could start and complete something interesting, and gave me a lot of real-world experiences to talk about in an interview, as opposed to the standard "In this database class I took..."
If you're effective for those "startup" hours, you can have something to show for it in a year -- maybe a business worth pursuing, maybe just an amazing addition to your resume.
In any case, going to college and working on a startup shouldn't necessarily be exclusionary, unless the startup proves to be successful enough that it makes sense to drop-out or finish your degree remotely.
I almost stopped reading after inferring that he believes being the CEO of a startup that your interviewer has never heard of, and for which "traction" probably can't be defined in less than 10 minutes of conversation, is a credential that will improve your chances at another company.
Selling a company is an accomplishment. Usually. (Sometimes that "sale" is a marketing fiction, but, whatever). Most entrepreneurs --- in fact, most of the entrepreneuers that get traction --- don't manage to sell their companies.