Anecdotes are nice but let’s look at some data.
Hyperbole aside, no one believes that biz schools are useless. That said, they underperform when it comes to startups.
Take Stanford GSB. It’s a great school, has a huge emphasis on startup creation, admits for entrepreneurship, and has produced some valuable companies. Yet, GSB is significantly behind two Stanford departments that are both smaller and don’t place nearly as much emphasis on startup creation. (There might be another department or two that are competitive.)
Of course, Harvard GSB does better by comparison wrt Harvard’s academic departments, but Harvard CS/EE isn’t Stanford….
MIT and CMU split the difference.