You basically created another language called “blueprints”, how can be C# meaningless? proof of gain? what about your main competitor?
Microsoft supports hundreds of languages and not just CLR (look what Azure support, visual studio, win 10 apps),
I’m not sure how they do that but I presume that they expose a well made set of API.
Xamarin for example could simply map to those API.
My impression is that everytime there is a version upgrade, everything can change, everything can became deprecated and being “open source” doesn’t help as much as a consistent set of API.
Of course this is just my guess, but really… saying “no proof of gain” seems more of an excuse