Specifically because in these companies they aren't optimizing for ethical behaviour.
They're optimizing for profit. And those damn ethicists just get in the way.
Funny thing: that doesn't typically happen to the internal legal counsel or accounting that's responsible for guiding processes/practices that are required for compliance or similar.
Why?
Because there's consequences.
I wouldn’t be surprised if many AI ethics responsibilities move to legal in the future.
I agree with you, but then we have HR for a reason.
Another example you might be familiar with is enterprise architects. When you spend all of your time in theory you lose sight of practical implications. Of course, since you only had the idea, when it doesn't go to your ideal it can always be blamed on the implementers.
I take it you've never worked with an in-house legal counsel, accounting department, or good ol' fashioned HR?