Some of it is about maximizing their balance sheet.
The factories that existing ICE engines are made in, both their build and every retooling has a cost; being able to maximize the saleable product from that cost is in the best interests of the balance sheet.
This is a challenge for both the US as well as Japan which is why you see each doing different weird things to try and kick the can down the road or ignore it. But that's a deeper part of the rabbit hole.
The factories that existing ICE engines are made in, both their build and every retooling has a cost; being able to maximize the saleable product from that cost is in the best interests of the balance sheet.
This is a challenge for both the US as well as Japan which is why you see each doing different weird things to try and kick the can down the road or ignore it. But that's a deeper part of the rabbit hole.