He could pay people for their work

Do forgive me, but I find this a bit of a simplistic standpoint.

We're not living in Lockean times anymore (if indeed we ever did) where you mixed your labour with nature and extracted your property from the land with your own bare hands, metaphorically speaking. There's no labour theory of property anymore in our complex multi-national, highly specialised societies.

As such, I do not believe in the idea of someone seizing an "opportunity", and I do not think it offers much ground for debate. I'd much rather prefer to debate the economical, regulatory, and financial environment of internet companies, which creates these "opportunities" in the first place, and how it's - in my opinion - exceedingly and unfairly favorable towards these companies, compared to traditional industries.

And that said, as others already pointed out, Dorsey, as a person, never participated in any Foss community.