I think you're ignoring reality if you think that online payments is somehow not finance. That he built companies that successfully competed with big banks on their own turf doesn't preclude the fact that he built on their turf.
If you don't see a mass exodus of traditional finance industry refugees into FinTech, you're not looking closely enough. Having worked at multiple growth stage FinTech companies (some in the online payment space), they have always been some of our most fruitful recruiting grounds.