Yes this is definitely a ongoing problem: New App Uninstall Mandatory Reason Selection: Useless!
In that post Shopify says:
developers have shown me examples of how they’ve gotten valuable feedback from merchants already from this new flow, so it’s unexpected that you’re seeing zero.
Which I find laughable considering how months later 98% of feedback is “Testing multiple apps”.
As far as “Not satisfied with customer support” it could be they tried to contact you but there was no “support” link or messaging widget or that your docs are lacking somewhere. We always follow-up to uninstall posts even the mostly feckless “Testing multiple apps” one.
Tracking user behavior can also be helpful. Maybe they did something and tried to use the docs to get more info or resolve some level of confusion but the docs are lacking.