And in the past 6 months of owning a Mac Mini, it's been frozen or "half-crashed" more than a dozen times that I've returned to it. The Apple-branded bluetooth keyboard works less frequently than the Logitech two-button bluetooth mouse I use with it, and even its performance it dodgy. Both iTunes and iMovie crash regularly, in fact almost every time I use them.
I find the same phenomenon on every piece of non-Microsoft software I've ever used. Firefox 2.0 crashes more often than IE5 ever did, and IE5 crashed A LOT. I have more issues making Apache, PHP and MySQL play nicely together (especially after updates) on my Fedora-run server than I can remember ever having my IIS based 2003 Server machine at the office.
I could go on and on with similar examples, but it really comes down to perception. I won't talk about business practices, who's done what to other competing companies, or talks of Monopoly or antitrust. I will say that on a software vs software basis, Windows competes in its segment just fine.
Is Windows perfect, or even the best? No, not really, but my experience with the software and OS's I use certainly lends to the case that it's not exactly the worst, nor is it completely and thoroughly flawed either.