Comment by int_19h

Not removing settings is in fact the standard and expected behavior for MSI-based installers (i.e. those using OS-provided tools). The framework is very paranoid about tracking the origin of every artifact (files, registry keys etc), and removing something in the uninstaller that installer did not add is considered a huge no-no. It is also what users generally expect - if they uninstall and later reinstall, they want their settings to be there.

Providing the ability to remove settings is something that has to be explicitly implemented (because the installer infrastructure cannot track files created outside of the installer), so relatively few apps actually do that. Those that do pretty much always do it as an opt-in. In my 30 years of Windows use, I don't recall a single example to the contrary.