The difference being that Microsoft had their monopoly to fall back on when their other attempts failed.
I knew this thread would fall into the trap of recursive "reasoning". Repeat after me, "a company cannot exploit its monopoly to become a monopoly". When they started they were a small scrappy company. Yes, there was luck involved, but they also had "the vision thing" going for them. MS viewed software as a viable business. They did not subscribe to the widely believed notion that software was just the necessary evil you bought from your hardware vendor to get your hardware to work. That vision led them to make decisions, like hiring business people and engineers, with the goal of building a long-term, sustainable business selling software that ran on *other* people's hardware. I am not saying they were the only ones to have such a view, nor even that they were the best. But it was somewhat controversial at the time, at least among the big computer hardware makers, and so I admire them for pulling it off and for being a major player in the "re-wiring" of the computer industry.