Big Social is obsessed with metrics, and proving value through metrics.
What metrics prove the Fediverse's value?
No one knows. Every metric regarding the Fediverse is at best conjecture. Nobody even knows its true size.
Hard to convince a CEO to buy into an idea when nothing is probable through metrics.
Nobody has validated the Fediverse as a place to make money.
Sure, tiny web-hosts might charge for services, but the average Big Social executive isn't looking to make tiny increases in a new venture. They want to 100x or 1,000x their ROI.
Somebody might eventually try this, but Big Social isn't going to be first.