The issue is that they're taking a tool with actual legitimate use cases, particularly maintenance and repair uses, and turning it into something to just push their own service. It'd be like a doctor saying you can only be healthy if you use his brand of fuckin... Vitamins or some shit,I don't know. It's got nothing to do with Microsoft, it's not automatically the worst thing in existence, it's just that Microsoft CONSISTENTLY does this kind of garbage, and it's one of those things that isn't overtly even a bad thing, you just have to look a bit.
So in short, I agree it is(was?) a useful tool, I don't agree that everyone is rabidly anti-microsoft, any more than anyone's rabidly anti-get-punched-in-the-taint.