MS zealots were few and far between Amiga zealots, Atari zealots, Linux zealots, OS/2 zealots, Mac zealots.. of all the OS advocacy newsgroups, the Windows one was one of the smallest in terms of posts.
Any MS zealotry left also pretty much died in the mid 90s, since then it was almost cult-free. Until now.
Been in this mess since the Commodore PET and there have always been platform zealots -- mostly from the Amiga and Apple II/MAC base. Windows was pretty much universally hated until Windows 95 (anyone who was there knows this), and OS/2 was pretty much getting equal coverage when 95 came out and there was an honest decision to be made between OS/2 and Windows 95 from a computer user standpoint (back then also, it was more enthusiasts instead of today's 'average user'). At this time, there were tons of OS/2 fans.
Really wasn't much Windows fanboyism/zealotry at all, most PC enthusiasts were trying different operating systems, a lot still used DOS, and as far as I can remember, the main reason Windows 95 "won" back then was because IBM forgot that you actually have to put OS/2 in a store in order for people to buy it.
From 95 to XP, I don't remember much fanboyism at all, just years and years of Microsoft being accused of being evil because they had the audacity to include a web browser in the OS. There was a lot of defense of MS, but I wouldn't call it fanboyism .. the browser war stuff was just stupid.
It really started with the Vista era where we started getting "news" articles about how people who find a problem with a Microsoft product have a mental disease and should be locked up (including Thurrott before he had a 100% change in opinion - I wonder if the amount of his paycheck has changed or frequency of free product deliveries has changed). It's also at this time that Microsoft stopped beta testing or listening to any customer feedback.
That's not to say MS are the only ones. In the time we live now, it's normal to ignore customer feedback and nowadays you don't even need fanboys who like the product -- you just need to hire people to write comments on software distribution sites or give tech "journalists" free products before they write the next article on some computer site.
Edit to add: I'm not specifically accusing Microsoft of buying fanboys -- I do find it odd, though, that lots of comments defending Windows from "normal users" tend to use a lot of phrases like "fast and fluid" and "better than ever" as if they're following a job aid. Sure, some people might, but most of them praising a product using the same terminology as the marketing dept when describing their own experience? Never have I seen that to such an extent except in the software industry where buying forum posts is accepted and SOP.