Creators are often happy with what they make(and often at times only makes sense to them 
). Hopefully OpenXR can help breath life into something new and elegant. On the plus it should help by it’s goal make things easier on Developers as they said not to have to learn each platform for the primary things. However it will take time to see if they can truly accomplish that goal.
We have seen other projects with similar ideals have mixed results. Java comes to mind; it’s original idea to create a universal scripting programming language to run on all platforms that simply supported Java.
Hopefully OpenXR truly succeeds in there goals.