I know why it happens. The damning indictment is, so do you.
Clearly, it's a detectable (and thus pointless) error condition. People have been complaining about this for ages, yet you do nothing, with your digits improbably inserted and a shrug along with a "yabut playstore" excuse.
Reinstalling doesn't work for me, but that's not really the issue here. You are preventing paying customers from having a seamless and carefree experience because of your focus on your own bottom line and the mechanism for enforcing it taking priority for YOU. It's shameful. The lack of a simple logic check for the condition is the technical disgrace, yet you expect people to reinstall, fiddle with the Google accounts on their phones, and so on.
It is NOT acceptable.