This has some weird amount of assumptions in it.
People may have any number of uses for pinephone HW. It's a nice SBC with display, touchscreen, battery, a lot of connectivity, very efficient suspend to ram implementation (find me a SBC that will suspend and run at 60mW), I2C and UART connectivity and a very nice GUI bootloader available for really pleasant SW development at any level.
Why waste any effort writing apps for Android, when you can only run them on Android? SW I wrote for Pinephone, I also use on my other Linux tablet unrelated to pine64, and on a Pocketbook E-reader, and on my workstation, without any weird hacks or emulation. It's a nice device/phone for developers used to GNU/Linux way of distributing software. If you don't want to, there's no "security" getting in the way of doing pretty much anything with the phone.
To devs who did nothing with Android, it's a massive waste of time learning all the idiosyncracies of Android, just to be able to make some simple app, or deal with restrictions like no audio recording of calls, no playback of audio into calls, background tasks limitations, etc. If I want to run rdbms on my phone to store data, I'll have it running in 1 minute. If I want to do it on Android and connect to it freely from whatever app I want, it will likely take longer if at all it would be possible.
"Why waste any more mindshare on the Pinephone?" just shows a complete lack of imagination
It's a versatile device that can be used for a lot of things. I can pop my Pinephone out of a backcover and pop it into this: https://megous.com/dl/tmp/1551fe95bdfade31.png and have fun making HW projects with it, for example.
