You've already said you never hire self-taught programmers so how would you know?

We have a lot of self-taught programmers in my generation in the UK (I think mainly because of the BBC micro programme for schools a few decades ago). I've seen awful CS educated programmers and I've seen awful self-taught ones.

The two best programmers I know, one was self-taught and one was not.

The worst programmer I've ever known was formally educated, could quote you reams of technical specs, advanced CS, and managed to write 20 lines of not working code in 3 months.