During that era (late-1980s) of personal computers, PCs had the advantage of being bootable in lightning fast DOS.Well duh, because they were used in Macs and EVERYONE knows that Macs don't have any games. Only Windows has the games, not those sucky Macs...
/me suddenly remembers what forum he's in
Probably because the x86 series of CPUs were sooooo much more common/popular and you could be guaranteed to sell 53487598347598347 copies of any software title for it. It was not so with the 68030, or any of the other 68k series of CPUs. They just never reached the same market penetration.
Macs had the Mac OS, and the game had to run on that, so there were some limitations as to performance. Also, most of the Macs at that time were black and white compacts.
Apple, also had this philosophy of not promoting games on the Mac as it was positioning the Mac as a business computer.