Android Otoh let's vendors get away with shipping binaries that work once on one Android version, making upgrades pain. And thus Android devices are generally stuck with the build they released with.
The Google decision to drop ChromeOS in favour of Android is going is going to be a huge disaster for Linux ecosystem.
It rather looks like Aluminium OS is the intended solution.
I don't see any problem with it being "locked down", in the sense that it doesn't sound any worse than Chrome OS or Android.
The open question is whether any open source release will happen worth a damn.
I think the problem is that it further normalizes computers where users don't have the final say. The more normarized systems like that are, the more likely app developers (and even websites, if something like web environment integrity were to be normalized) are to lock out users on systems that aren't so restricted.
I wish I didn't have to care what kind of computers most people use, but in reality, it matters what's popular.