Of course that varies by jurisdiction, but yes the UK, EU states, and US have a (variously termed) concept of 'protected characteristics' that cannot be considered in hiring.

I agree with you, I don't see how affirmative action is compatible with it, whatever one's thoughts on it, but it seems to be an area nobody's wanted to touch. (Consider that you'd have to be the non-marginialised, thinking yourself wrongfully not-hired. Hard to imagine - in the UK - political appetite for it as a state lawsuit or regulation.) I wouldn't be surprised to see it blow up at some point though.