People choose Microsoft because it offers benefits that they consider worthwhile, and as Microsoft's success as a business shows, people are willing to pay for these benefits.People paying money for products is only one half of a healthy market. Innovation by the capitalists is the other half.
Microsoft is not innovating because it doesn't have to. It has an extremely solid framework in place ranging from software interoperability trade secrets to software patents to vendor lock-in contracts, all to ensure that no one will be able to compete with them legally or that the cost of starting up will be so great that no one will bother.
Their entire business foundation is placed upon a government intervention known as copyright, which has also not served the market. If it were 14 years and if software copyrights required registration of the machine-readable source code with the copyright office, we would already be benefiting from the Windows code of NT 3.1 vintage to serve interoperability efforts, even when they are unwilling to provide interoperability details themselves. However, instead, they are allowed to retain a perpetual monopoly on their software legacy, and any interoperability must be attained through reverse engineering. That is not a good formula for competition.
Without competition, innovation is not happening at the rate that it would in a healthy competitive market. You can sit there and argue all day that Microsoft deserves to reap the riches of their monopoly position without government interference, but every day they sit on their haunches deciding whether it's worth bothering to improve their products, progress in the state of software engineering and the leading edge for users is being held back. I don't know what dogma you subscribe to, but economists seem to have a pretty good formula for improving society, and competition is a fundamental basis of it. Where competition does not naturally exist, it is government's job to try to stimulate it as part of a successful economic policy.
It is utterly ridiculous that we have to depend on open source loving hobbyists and small businesses for the little innovation that comes out of the software industry today. Microsoft may be a monopoly, but they are no market leader. They are a disgrace to the computing industry. I hope this decision changes them permanently for the better.