Indeed. Or they would have stuck to using Windows, or some commercial Unix.

Sadly i feel that more and more upstream wants it both ways, be able to push their latest and shiniest, and keep ignoring any need for interface stability etc.

Frankly i suspect the end result of the likes of Flatpak will be that upstream push whole distros worth of bundled libs, just so they don't have to consider interface stability as they pound out their shinies in their best "move fast and break things" manner.