Not all users have shell access either.
If they upload to the right location in the first place, then they likely won't have a problem - the new files will inherit the security context of the parent directory. It is only when they upload to a location with different protection defaults and then move to the new location. Even copying would work fine, as noted, as it doesn't preserve protections by default unless you specify the corresponding option.
Does FTP support moving? If not, then the issue of not having shell access goes away, because the user can't upload and then move.
