back in the eighties presenting an atari or amiga to a company was like giving a 1000E wine to a monkey. corporate but also most mainstream buyers did not even have a clue about the true potential of available hardware. lazy as humans are, most chose a brand that had been around a little longer than the competition and already had a reputation for reliability. microsoft basically didn't jump at the opportunity but was launched by ibm, who didn't monopolize their product well enough to prevent *many* clone builders from copying and improving their products. all this while all other major platforms remained closed until the 90's or even today- so the market got saturated with pc clones. and again, lazy as humans are, they tend to buy what they know, so if your company already uses pc and you see pc in the majority of shops too...
i don't think the majority of monkeys wants to stop drinking supermarket wine anytime soon