Just like any browser could run on the Mac or Linux, and ignore Windows if they preferred. Or Dell could sell Linux machines, and not Windows if they didn't want to.
The point is that Apple and MS both used the fact that vendors need them to make money (and while competitors for both exist, competitors yielded less likely return), and leveraged that position.
The point is that Apple and MS both used the fact that vendors need them to make money (and while competitors for both exist, competitors yielded less likely return), and leveraged that position.