Why hasn't Springfield bought out the 45 Super trademark from Ace Custom Guns?

[colorado]

I have a 1911 Springfield V16 Long Slide in 45 Super and it's a fabulous gun. It will shoot either 45 ACP or 45 Super with a spring change and it's built to handle the 45 Super (230g at 1150 fps) all day. I shoot Remington 230g Golden Sabres at 1150 fps for my self defense round. It's mystified me why Springfield never bought the trademark effectively letting Ace Custom Guns kill the cartridge.