Certainly there are countless examples of faculty serving on SABs of start-ups using technologies coming out of their labs. [I agree faculty rarely leave jobs for this, but then, they're not typical operational people anyway...]

I agree regarding metrics: if it's absolute returns, there's little hope for the univ-associated incubator model. This is at least partly because you might be obligated to spend time with teams on which you would otherwise pass.

But, clearly the university has numerous metrics including faculty/student retention & opportunities, community development, publicity, etc.

May I ask -- is your negative perception rooted in experiences with incubators?