I’m still curious about whether he was unable to finish college for financial reasons. The economy and job was pretty bad in 1990 when he expected to graduate.
He quit because there were better opportunities available to a person of his talents (a common enough story for people with talent).
John McCormack of the Weekly Standard:
When I asked Walker about his college departure last August, he observed that a local TV anchor had likened his experience to that of a number of successful entrepreneurs who left college early. "Once somebody tried to take a dig at me. Ted Perry, the anchor on Fox 6 in Milwaukee … he did this whole thing where he pointed out: What do I have in common with Bill Gates, Steve Jobs, and Zuckerberg? All of them left in their senior year. Arguably, they did much cooler things than I did. I went to go work at the Red Cross. They started these amazing companies. But it’s the same principle. It wasn’t like getting kicked out or leaving early. I had something to do,” Walker said.
Actually, Jobs dropped out during his freshman year at Reed. Gates dropped out during his junior year. That's from memory, and I'm too lazy to look up the Zuck.