In this case it really seems this windows convention is bad though. It is uninformative. And abbreviations mandate understanding more file extensions for no good reason. And I say this as primarily a windows user. Hiding file extensions was always a bad idea. It tries to make a simple reduced UI in a place where simple UI is not desirable. If you want a lean UI you should not be handling files directly in the first place.

Example.zip from the other comment is not a compressed .exe file, it's a compressed archive containing the exe file and some metadata. Windows standard tools would be in real trouble trying to understand unarchived compressed files many programs might want to use for logging or other data dumps. And that means a lot of software use their own custom extensions that neither the system nor the user knows what to do with without the original software. Using standard system tools and conventions is generally preferable.