I'm a Linux guy too.
Hopefully I'm not brainwashed, but maybe I am a bit of a cynic when it comes to Microsoft. It's my belief that human beings, as a species, are capable of creating things that are much better than what Microsoft produces. Unfortunately, it seems like a large number of tech users think the word "Microsoft" is synonymous with "software." I know that this sounds crazy to some people, but I truly think Microsoft stifles natural improvement to an extent. Not unlike the way Wal-Mart stifles the free market. The general reasons for my diminishing respect for Microsoft are...
-Non-standard and MS proprietary protocols are ubiquitous in their software, which makes interfacing with it unnecessarily problematic. (e.g. compare Exchange/Outlook to Zimbra Collaboration Suite)
-Everything leads to another license (e.g. CALs)
-Flawed and limited logic in software (e.g. compare Visio to LucidChart)
-Many Microsoft products are just plain unstable, but nobody notices because it's always been that way.
-Its expensive for no good reason
-Everybody uses it, because everybody uses it... that's a loop... and loops are bad
I don't like to be cynical, but after so many years of this... it just gets old.