Monopolies are not inherently bad. If MS has a monopoly on the desktop, so what?
One reason MS is despised is because they use that monopoly to force their way into other markets. Be it server, handhelds, etc.
A monopoly is always open to competition if someone decides to take it on. In MS's case that was originally(?) OS2. MS is bad because of how they have (illegally in some cases) eliminated that competition, ie thru strongarming "partners" because of the monopoly status.
If OS2 or DrDos had been allowed to fairly compete with MS, we would likely be seeing an entirely different computing landscape today. Linux would, ironically, probably not exist, because we'd all be using open source OS's & desktops from MS, IBM, Sun, etc.
And I think it was yesterday that I saw an article somewhere saying that MS would have to open source at least part of Windows if it wants to survive.