Microsoft own their OS, they make the rules, if they want to ban mac stuff they should be allowed to. Try asking them how just bundling internet explorer went for them.
This is a really, really poor analogy.
They did this during a time when people had to literally BUY internet browsers. Yeah, Netscape and Internet-in-a-Box and the like all required you to physically go to a store and purchase them -- as one of their names alludes to, in a box.
IE came in, already there, for free. They killed Netscape entirely with that -- and Netscape would then hand their web browser development to the open-source community, specifically some random company called Mozilla who would later turn it all into something I'm sure nobody has ever heard of called Firefox which, they say, we all allegedly benefited from -- and in short order, all browsers became free.
These are 2 services that both have costs associated with them to use them. They're offered at par. They also don't exist on a platform with the size or scale to kill the other as Microsoft near-instantly did to Netscape with their, at the time, superior IE 4.0.