There are quite a few arguments (in each direction) in the Mac vs PC debate, but I think this quote from John Gruber sums it up perfectly:
People who love computers overwhelmingly prefer to use a Mac today. Microsoft’s core problem is that they have lost the hearts of computer enthusiasts. Regular people don’t think about their choice of computer platform in detail and with passion like nerds do because, duh, they are not nerds. But nerds are leading indicators.
They’re a software company whose primary platform no longer appeals to people who like computers the most. Their executives are either in denial of, or do not perceive, that there has emerged a consensus – not just among nerds but among a growing number of regular just-plain users – that Windows PCs are second-rate. They still dominate in terms of unit-sale market share, yes, but not because people don’t recognize Windows as second-rate, but because they don’t care, in the same way millions of people buy metric tons of second-rate products from Wal-Mart every hour of every day.