Also a factor was that while clone machines existed of the IBM/Intel systems and earlier Apple and other 6502 computers, often out of Taiwan, the other vertical vendors managed to keep tighter control. 68k equipment from 3rd parties for Macs and such was much harder to come by. While that temporarily increased their margins, long term it meant that PC component costs kept dropping until you could get a 586 desktop that did 75% of a SPARCstation or NeXT for 30% of the cost.
For businesses, the hardware cost of technology is much smaller than the investment they make in their workers or software systems. Having multiple interoperable hardware vendors to choose from in addition to an OS obsessed with binary backwards compatibility made Microsoft/IBM PC clones the obvious and safe choice. This created economies of scale that inevitably shrunk the market share of the other systems (Commodore, Atari, etc). Apple only managed to hold on by dominating the education and creative markets.
