Windows is an amazing operating system, that worked better, was better marketed and better supported since the beginning.
That does not match with history, though, except for marketing. Support is a more complicated issue (and has different facets, like comparing maintenance agreements and paid support, to freely available documentation and the veracity of said documentaton), so I'll leave that out.
Microsoft did awful shenanigans with their OS to try and shield both Office and Internet Exploder from competition. They were convicted for monopoly position abuse against WordPerfect, for example. It is less discussed, but they also made a lot of possibly illegal marketing deals, where offering competing products, especially computers with Linux preinstalled, would mean huge cost increases for resellers. In 2000-2010, when the first Linux-based minilaptops (netbooks) were first introduced, some larger resellers faced a lot of pressure from Microsoft, and it is not at all clear how much that impacted the market.
Even today, it is very hard to buy a computer without an OS preinstalled: this is often called the Microsoft tax, as they were behind that push.
Point is, MS has never "played fair", using the quality of their products as the key point. Quite the contrary, many of their products have crashed in the first big reveals, and have been instrumental in the emergence of the
"have you tried turning it off and then back on?" culture, so that users now accept products that crash and lose data as par for the course.
Linux developers made some really bad choices as well. The main one was allowing out-of-tree graphics drivers. In theory, it should have been a good idea, as manufacturers (AMD and NVIDIA) do have the resources to produce good drivers; but for business and logistics reasons, they never could. ALSA/PulseAudio over OSS was another, and made audio tricky for quite some time; ALSA-"internal" library-kernel interface changes still cause occasional issues today. SystemD is yet another; we'll find in a decade or so how bad idea such centralization is, compared to the old Unix philosophy. In particular, there is a reason why systemd is not used on any embedded devices.
Out of the many kids that found Linux to be cool, how many do you think thought to themselves: "hmm... grandma' will love this!" - close to none, right? why?
There are lots of grandmas using Linux. Heck, my mom refused to touch computers until she was 65 years old, but when she found all her grandchildren were on Facebook, and got an Android tablet (which is based on the Linux kernel, just uses a different Desktop Environment), she took to it like a duck to water.
I guess I should count myself as "radical" too, having used Linux since 1995, maintained a LOT of Linux servers and even a few clusters since 1998, and using Linux exclusively on my own machines since 2005 or so. However, I find nothing offensive in this thread. I don't care what others use, or what they think about using Linux. It is only arguments like "Linux won't be X until Y", or "Nobody should use Linux, because Z" that piss me off -- and not because they're about Linux, but because it is horrible advice. I don't care how popular Linux is, because why should I; it makes no difference to me. Not having to deal with casual users who want stuff without contributing back is actually preferable to me, compared to everyone using Linux.
You want to play games? Run Windows. You edit video? Use a Mac, or perhaps a Windows machine (I'm not up to date on the video editing software anymore, however). Write portable code? Run Linux, with lots of RAM and storage, and run other OSes in virtual machines. Use the tool that suits the job, instead of trying to convince others everything is really just nails, and your preferred hammer is the only tool anyone ever needs.
We could talk about how user interfaces haven't really advanced at all in the last 20 years, only adding "bling"; and that if you tried using say Mac OS 7.5.5 and its contemporary software like MS Word 5, you might start seriously wondering why current Windows and Mac OS (and most desktop Linux distributions) spend all that memory and CPU power, as it sure does not look like it goes into making humans more productive, and the tool more responsive.
Me, I'm pretty sure people are just too stupid to demand better products. They want bread and circuses instead; bling, not robustness.