Would have english been incorrect if you said "Would have Satanism been..."? Yes, would have it been.
There are good reasons for Satan being part of the name. It attracts some, and repels many others. The philosophy fits the devil's persona so well, why not use it? After all, God was created in the image of man, and Satan was created in the image of the Satanist.
Coulda, shoulda, woulda. Why think about what might have been? Satanism is already here, it's too late to stop the Age of Satan. IT HAS BEGUN!!! SO MOTE IT BE!!! MWA-HA-HA-HA-HA-HA!!!!