Why would they make cards to make it run a different computer?
The PC was the "standard" business computer at the time, and most businesses were paying big money for the software licenses. In order to entice businesses to embrace the Amiga platform, Commodore wanted to offer a way for businesses to buy Amiga machines while still allowing them to run all the same programs, open all the same files, and connect to the same networks.
I think Commodore went about this in a wildly convoluted way with the A2000, but that's Commodore for you.