Only wrinkle is that Mono was originally a .NET runtime for Linux. So they weren't embracing an external standard but a knock-off of their own. But I still agre

Only wrinkle is that Mono was originally a .NET runtime for Linux. So they weren't embracing an external standard but a knock-off of their own. But I still agree with elements of your statement in principle. However, giving Mono back to open source is an interesting development and I don't know how it fits in your narrative.