Without knowing the background of Android dev I wouldn't want to condemn anyone for anything, whilst I don't disagree with what you're saying. As an end user, this solution is perfectly acceptable for me, at least for the next few years until my eyesight goes the same way as my hair.....
Not sure if you think I was condemning anyone or not, but I wasn't. Changing the global font size on the phone is not going to work for many people though. Take it from me, those next few years will be here before you know it.
Having a setting within the app for font size for the app might work though.