Because Nintendo jealously guards even the ideas that their IPs create. You just saw them go to the courts to make their patents be a little more vague just so they could try to take down Palworld. And they know that as long as they can corner the market on those specific experiences you’ll have to come back to them in order to get it. It’s very much like a drug dealer getting rid of other drug dealers that might come into their neighborhood so that the only drug is their drug and the only place to get it is through them.