Because there is no dedicated RP server, people can get banned for RPing IC. People who don’t RP who see someone RPing in /s, and don’t know they are IC because they don’t RP; can ban you for spamming or offensive language and the mods will ban you because they love the ban hammer in FFXIV.
That’s the problem with not having a dedicated RP server. You HAVE to be in a specific group for it, and you HAVE to RP in /p chat. You can’t just wander around and randomly start RPing IC.