Easy: because those roles you referenced are fed by a career track that starts in university programs with a much better gender balance. Some of those role are MBAs, and some of them (the project management stuff) are generic liberal arts with some industry training (like PMP).

That doesn't mean that the solution to the problem is in university enrollment, but it does explain why it's easier to find women in non-tech roles in software companies: it's because those roles don't require an early life commitment to a career in technology.