Vivi knows the score, SE would have a really hard time being a licensing business; licensing something like that requires a LOT of front-facing customer service and support. They'd need documentation for all aspects of the engine in multiple languages that would need to be updated regularly, plus needing support staff that would be knowledgeable about the tech and be able to support customers speaking those same languages. It's really not as simple as just selling licenses, it's a big business investment.