I don't use their products because I am an IT professional. I know what they do, and (basically) how they do it. I've been following MS since they were created, and I was using Windows products up through the mid 90's.
I have experience on both sides. You are free (of course) to ignore my comments/opinions. You can disagree with them. But they are not irrelevant.
Something I've noticed over the years is that the most anti-linux/open source folk tend to have no experience with it whatsoever. OTOH, it's almost impossible to not have to deal with microsoft to some degree.