Why Torvalds?
UNIX is also basically irrelevant unless you are talking about macOS technically being UNIX, so I agree with the kids.
The idea that Linux is a monoculture is also hilarious to me. That umbrella includes things like RHEL, SteamOS, Bazzite, Android, Chromebooks, Gnome, KDE, dwm, i3, your robot vacuum, car infotainment systems..."Linux" is the exact opposite of a monoculture.
Also it isn't as if BSD, FreeRTOS, Aix, INTEGRITY, SmartOS, Illumos, QNX,... don't exist.
This is more a limitation on the architecture - virtually nobody has power arch hanging around to play on.
It’s also not a culture at all because it’s a kernel.