Open != good. "Not Invented Here" doesn't just come about from anticompetitiveness or stubborness, sometimes there are real problems encountered - especially in

Open != good. "Not Invented Here" doesn't just come about from anticompetitiveness or stubborness, sometimes there are real problems encountered - especially in edge cases or at scale - where trying to fix them through navigating open standards vs making your own thing that works better for you is a really viable option. See also Google's reinvention of things like build tools internally. Lots of open source versions, but they caused plenty of engineering pain of their own.