Because Nintendo is unable to sue a company from another dimension, and if they could, I'm sure the Diamond City courts would not even bother, for the judges are probably too busy playing WarioWare Inc.'s amazing games. ;)
Ashley's attraction would be the Horror House. Instead of a thrill ride, Orbulon would have a planetarium with many neat visual tricks. Dribble & Spitz would have the Bumping Cars or Go-Karts.