Phone phone phone phone.....no..!
Just because it *can* be a phone OS, doesn't mean it *has* to be a phone OS.
As has been said previously in this forum, Moblin has been used in automotive applications, among others.
Meego was touted a automotive, media devices, and much more, but only really hit the mobile world via Harmattan on the Nokia N9.
Tizen is a step further on from that, and is aimed at Intel hardware in various situations from industrial control, right through to ..... mobile devices.
SailfishOS carries on that theme. Not just aimed at mobile phones, even though Jolla have created a great "beta test" device.
So stop fretting about it "not taking off as a phone OS". If it does, it does, if it doesn't it doesn't.