Windows wasn’t my first operating system. I don’t even remember what my first was, but it ran on top of DOS and had a 5 and a quarter inch floppy drive. I’ve used pretty much every windows desktop version since 3.1, but really only installed or maintained XP, 2000 server, and Windows 10 on my own hardware. But I’ve also installed and maintained various Linux and BSD distros since about the turn of the millennium, including a brief relationship with a Mac laptop with OSX.
There was never a switch. I always ran whatever I could get working that would get the job done. For some tasks that was Windows, either because it was good enough and came pre-installed or it was required by the software I needed to run for school or work. I’ve handed in many assignments on 3.5 inch floppies. I haven’t maintained a server with windows since Windows2000 server. I’ve tried Slackware and Corel Linux. I bought SUSE Linux in a box from a big box store. I’ve gotten those brown Ubuntu install CDs in the mail. I remember being delighted with the development of BitTorrent because now my downloads would check themselves for consistency as they downloaded the ISO. No more getting to the end of a download only to discover the md5sum failed to check. I’ve used Knoppix and Clonezilla for system recovery.
There was never a change. I’m a tech nerd that likes Linux, not a Linux nerd that likes tech. But, it was the way windows kept destroying my Linux partitions that drove me away from dual booting and installing windows on anything in general. Also the windows situation with viruses, updates, and lack of security that drove me away unless compelled. Now windows lives on its own hardware or in a VM for me.
I’ve also found that the documentation online is much better, or at least easier to search, with Ubuntu in particular than any other distro. This is probably mostly due to popularity at this point as you said, but I think they got that popularity because of the straight forward and easy to digest documentation. And I’m not just talking about self-help support forums, I mean published and polished wikis and guides hosted by the distro itself.