Why does "Purge" not remove everything related to an app? [duplicate]

Solution 1:

The package management never touches any files in a user's home folder so the files there will stay even if you purge a package.

Solution 2:

As far I know purge removes a package and it's system wide configuration.

Purging a package wont remove user configurations because what ever created in user directory belongs to user and they are not related to system.