They signed a contract with Sony to develop the CD, backstabbed Sony and that created PS1, then they signed with Phillips, backstabbed them and thus the bad Phillips CD-i.
So yes it seems like you are more lenient with companies breaking contracts than with companies that without contract gone for a better deal. Don't remember you calling Insomniac traitors when they made Sunset Overdrive.
I dont know the full story between what happened with Nintendo and Sony, but i do know that Nintendo werent the only ones saying no to Sony, Sega said no to them as well. Clearly there is more to it than Nintendo just packing up and leaving, there is speculation Sony wanted more and both Nintendo and Sega forseen Sonys plans. Who knows and this is not the topic.
However if what you say is true than sure Nintendo broke that code but we dont know the full backstory, we only know from the outside. Now this is about Square moving one of the most established IPs and locking it exclusivity to a rival conpetitors platform. Thats why Nintendo was pissed.
I dont understand how Sunset Overdrive is even comparable to this type of move. If Ratchet and Clank crossed to Xbox than id see your point, but your point on a new IP that Sony didnt want is not the same as Final Fantasy.
Eeeeerrrr let's say again so you get it. Sony and Nintendo already had a contract, or do you really think they developed the prototype for SNES without a contract? And that prototype is what them got them started on Playstation.
From what is told Nintendo later thought the contract was of to much benefit to Sony and left. Still that is Nintendo breaking a contract they signed because another party were going to receive more money than them. Funny enough is someone thinking Nintendo would be naive to have signed the contract without reading. So it is much more probable that they were fine with the terms of the contract, but later thought they would review and think Sony was getting to much out of it, and you may disagree but that is where greed would come in place.
Nintendo didn't broke a code, they broke a contract.
There would be no way of R&C crossing to Xbox simply because the IP is OWNED by Sony, FF was never owned by Nintendo it was just released over there. Is Sony pissed at Universal or Activision because they lost Crash and Spyro IPs even when buying the studio just because those IPs belonged to another party instead of the studio? Hint, nope.