It's not a question of ethics. It's capitalism. It's not like buying the software hurts anybody, you're just spending money. You could make the same argument

It's not a question of ethics. It's capitalism. It's not like buying the software hurts anybody, you're just spending money. You could make the same arguments about a lot of things, including the US auto industry, Nintendo, and Hollywood. Hollywood films were imposed upon European countries after WW2 as a way to spread American ideas and culture, and it's partially because of that that Hollywood has been able to get so big. So now is it unethical that people 'have' to spend money on big blockbusters because they don't live in a big enough market to make indie films worth showing? Or similarly, would you say the US car business is unethical because it was involved in strategically eliminating trains in various parts of the country so more people would drive cars? (Look the Nintendo one up if you're confused, it's from the NES/SNES days.) If this was about food and we were all being forced to buy McDonalds because McDonalds forced everyone else out of business, then I'd agree that we should be up in arms. But this is software. Or rather, it's JUST software. Computers would cost a lot of money with or without Windows.