It is surprising that FB would allow the business analysis side of the house to grow equally (or even at half the rate) engineering based on how Facebook was founded and by whom.

When someone has a team or an area they are responsible for, they will try to make that team and responsibity grow as much as possible, whether or not it's good for the organization. This is not obvious to the perpetrators.

I don't really think Mark Zuckerberg is the source of having an aimless PM org. I think that he should serve jail time for wire fraud and overseeing a defective product that causes people harm. But I think that's disconnected from his abilities and vision as a founder, engineer, and creator of one of the most successful companies in the world.