This is false, and also misses the point.
I went through two recruiting cycles at HBS (Harvard Business School), which is one of the largest (~1000/yr) and most representative business schools. I did not see a single position advertised which required actual engineering experience. I was also one of three people (in 1000) who had a job before school which required writing code.
There were plenty of companies which would have loved to hire a solid engineer, but the job they'd be hired into would neither require nor use those skills. I could certainly go work in Product Management at Google, for instance; but why would I want to? My better path to VP at Google would be as a coder (if I wanted to be a VP at Google).
> There are few CTOs because a 50K employee company only has 1 CTO. Others are CEO, COO, CIO.
There is 1 CTO in the HBS alumni database. There are more than 36,000 CEOs. CEO-CTO is probably ~2:1 in the real world.
ps: data mining the HBS Alumni database is fascinating, btw!