Why should they pick something? I thought the whole point of this was to build open hardware and let me pick something?
If you want a manufacturer to decide for you what you should run on your phone, maybe just buy a Samsung or apple device. They've already got it figured out also.
They're just picking the default SW. You can still run whatever, including any other bootloader or OS. It's not like it's locked like a typical Android phone.
Many Android phones are also open like this as shown by pmOS: someone somewhere has to work on mainline Linux support and normally mainline doesn't really work and there are still some downstream patches left, meaning you can't run what you want unless you have a patched kernel (the same it true for the PinePhone and PinePhone Pro).
If you want a manufacturer to decide for you what you should run on your phone, maybe just buy a Samsung or apple device. They've already got it figured out also.