It is illegal. It is just as insidious as gambling. It destroys the integrity of the game.
Like Rose Cora knew it was illegal when he did it. He deliberately violated the rules. He is fundamentally dishonest. Every person I ever fired for cheating or illegal behavior on the job always apologized and said how sorry they were. Yeah they were sorry alright, sorry they got caught.
Cora is a cheat, he defrauded the fans, he defrauded his opponents, he defrauded his bosses, he cost them their future. He deserves to be banned from baseball for the chest that he is.