You can still invite people in private. plus some people use codes to mod their stats and for the sake of modding cars.
But i get your point... if that's your only reason then you're also the reason why the CID's here gets banned so fast. If you want to kill people, play legit don't be a pussy and used codes. coz i don't get your logic... you want to kill other players but they can't kill you?.. you're fun to play with.