Isn't (at least) the Hololens the starting point?
The hardware for ambient light AR also sucks, it’s why HoloLens, magic leap and such are not compelling. It’ll be a while before that’s a viable option (and why Apple is committed to pass through currently).
I think Microsoft didn't have the confidence that it could be a mass market/consumer device at its price.
(It is interesting that with the Disney section of the keynote, Apple seemed much more directly was flirting with consumer/mass adoption.)