Problem with BSD license? We are discussing two separate issues here

1) Ability to unlock or root your device to run any OS

2) Having access to an open App Ecosystem.

The GNU license doesn't help with either of this issues. There are plenty of GNU/Android devices shipped with locked boot loaders. And nothing is stopping Google from locking down their App Store like Apples except a different corporate policy.

I don't think there's a problem with the BSD license, but the GNU license is actually supposed to help with those issues, just not the version used by the Linux kernel (v2).