Disabling this feature enables traders and or other people trying to constantly cruise away from interaction. It is very difficult to type out roleplay notices (engagement or not) and to stop the person who is spamming cms and trying to cruise away. There are already several features of the game that are accepted that enable this sort of behavior, setmsgs are a balancing mechanic in that sense. The people abusing this to break the rules should be punished individually rather than stripping the mechanic from the collective who are not all using it maliciously.