That's great and kudos to the FB engineers.
However, engineers always love to build stuff. Once it's built it needs to be supported in all perpetuity and that's where issues arise. FB now needs a SDN team to keep their thing running, up-to-date, following innovation and industry standards, respond to zero-day-exploits, and all other things associated with BEING IN THE NETWORK SOFTWARE BUSINESS.
Give it a few years and that team/division will become so big that it will warrant a spin off or they will just go to an established product.
Biting the hand that feeds IT
