By the way, I read this quote as a sincere attempt to understand what was going on in the mind of some people. I am afraid the actual explanation may be a bit more prosaic. A monolithic kernel might -o horror of horrors- be quite mundane. And where is the tenure in that?
I'm a confirmed Linux user [switched from macOS], but to me it's clear that git dwarfs Linux in terms of sheer _significance_.
Sure, Linux is what runs most big systems and that is really cool, but if Linux hadn't come around, there was already BSD [which is also good and a lotta my buddies were advocating in the mid-late 90s]. But git is quite unique and has / had no easy substitute. I don't [personally] know a single technology person who doesn't use or interact with git daily. And the benefits of reliable, free/open, and distributed version control are just monumental for the average working code stiff.
There was Monotone, which was git's main inspiration. If it weren't slow as molasses, we might be using it today instead of git.
While I like Linux, that may be overstating the case