There were quit a few off them--by number of starts per year per person Caltech was actually generating startups at a higher rate than Stanford. But almost none of those Caltech startups were doing anything that would bring them to the public's attention, or even to the average HN reader's attention.

For example one I remember was a company developing improved ion thrusters for spacecraft. Another was doing something to automate processing samples in medical labs.

Also almost none of them were the "undergraduates drop out to form a company" startup we often hear about, where the founders aren't actually using much that they actually learned at the school, with the school functioning more as a place that brought the founders together.

The Caltech startups were most often formed by professors and grad students, and sometimes undergraduates that were on their research team, and were formed to commercialize their research.

My guess is that this is how it is at a lot of universities.