This functional rejection of the possibility of sex based differernces is a big part of why we are where we are, inlcuding in areas like women's sports.
"If people knew there were biological differernces between man and women physically, it might be difficult to get them in to jobs like firefighter, or soldier, in equal numbers."
Well, fine, yes, but not because people are sexists. But because it may be that fewer women will qualify.
Is it the case that somewhat fewer women are inclined to be CEOs or perhaps have the qualities of CEOs, for biological reasons? Maybe, but if so, it's not actually saying it that creates the issue, is it?
Peterson's view on psychological differernces between men and women isn't actually that far out - it's not universally agreed on but it's a common viewpoint among psychologists. And it doesn't deny sociological and learned differernces. He bases it on personality trait differernces - at the population level, and which are on a spectrum - that are consistent across cultures, which is an indicator that they aren't learned. As is the fact that they show up even wheer you would expect people to have learned differently.
He says himself that they are not massive. But I think we are all educated enough to know that even small differences like this in populations can have a significant effect sometimes in terms of things like who goes into what kinds of jobs.
As for not wanting women as leaders in business? I have seen him talk about this in interviews and I think he finds the accusation flummoxing, not least because he spent a lot of time in his career helping women who were in roles like that learn how to better manage things like excessive agreeableness in order to progress in their careers by being more assertive.