- The misconception that you need to "know linux" to use a computer with linux.
You need to "know linux" to administer linux servers, or contribute to kernel development. My wife is a retired pharmacist, and she uses exclusively a computer with Linux since around 2008. She knows that's Linux, because I told her so. If I had told her it was a different version of Windows, she'd be using it anyway - she was using win95 at work before, so any current windows would have been a big change anyway (granted, nothing like gnome, that's why I gave her kubuntu).
This misconception is fed by "experienced" Linux users who like to be seen as "hackers" just because they "know Linux".
Nobody uses the OS. You use programs that run on the OS. My wife doesn't "use Linux". She uses Chrome, the file manager (whatever that is in the ancient LTS Kubuntu release I have there and update only when LTS is over), LibreOffice Writer and Calc, a pdf reader (not adobe's, whatever was in the distro), the HP scanner app. The closest she gets to "Linux" is occasionally accepting the popup asking for updates.
Users shouldn't need to care about which OS (or which distro, for that matters) they're running their apps on. The OS (and distro) should be as unobtrusive and transparent as possible.
- Distro hopping cult. It's ok to try a few distros when adopting Linux, or even flirt with new ones after you've already settled with one. Even keep doing it forever, on a secondary machine or live usbs, if you're curious.
Doing it forever, on a primary machine is stupid; NO FSCK DISTRO WILL BE PERFECT. Windows users whine and cry every time Microsoft shoves a new and worse Windows version up their SSDs, but they stick with Windows anyway.
Distro hoppers hop often because they give up at the first inconvenience. They never feel at home or make it their home, because they never actually use their computers for long enough with any distro. They are more focused on the OS than in using the computer. Nothing wrong with that, but they'll forever be "linux explorers", not actual "linux users".
There will always be some other that has that small thing that doesn't come default on this one. There will always be compromises. It's like marriage. Commit, negotiate, adapt. Settle down ffs.
The OS/distro shouldn't be important for the average user; the OS/distro shouldn't get in the way between the user and the apps, which is what the user uses.
Of course there are distros with specific usage in mind (pen test, gaming, video production, etc), as they conveniently have all main utilities packaged and integrated. But for real average user apps, the OS shouldn't matter to the end user, let alone look like the user should know what window manager or packaging system they're using.
Then when they are faced with dozens of "experts" discussing about which distro has the edge over the other, and the gory technical details of why, and comparing number of distros hopped, well, it sounds like Linux is a goal by itself, when all they wanted was to watch YouTube and access their messages and social media.
When my wife started using a Linux computer I didn't tell her which distro was there (she probably knows the name kubuntu because it shows during boot). I didn't give her a lecture about Gnome vs KDE, rpm vs deb, or the thousands of customizations she could have now. "You log in here, here's the app menu, here's chrome, this is the file manager, here's the printer app". Done, linux user since 2008.
Linux will never be mainstream while we make it look like "using Linux", or "this distro", matters, and that is an objective in itself. Most users don't care. They want to use their apps.
I like a wide variety of music styles, from Bach to Deep Purple, from Sade to Front 242, from Wagner to Technotronic, but according to my family, none of them were created after the 90s.
And I dress jeans with whatever is on the top when I open the shirt drawers. But I open the polo shirts drawer on workdays and the t-shirt drawer on weekends. My wife sometimes shuffles my clothes in the drawer so I don't keep rotating the same ones forever. She also sometimes throws away some of my clothes, unannounced. Can't believe she threw away a hoodie from my uni, brand new, from 1988. I can't say fashion means much to me ;-)