It's a Unix-clone using a monolithic kernel made in a time when Lisp machines existed and microkernels were all the rage. It used ANSI C which, to be fair, was new at the time, but stuck with it, in the face of C99 and C++.
And, as a windowing system, it still uses X11, a system designed in the mid '80s. There has been a very slow migration towards Wayland (which is now already 10 years old).
As it's scripting language it uses bash (1989), which inherits a lot of it's characteristics from the Bourne shell (1977).
Yes, in the case of Linux may be a little bit biased as OS development back than was still more mature than front-end is now, but still, the principle still holds: "slow and steady wins the race".
As in article if people share code to be "ninja", "rockstar" devs that is wrong approach and I don't want that code. Because solution is not honest, not reliable and probably will be dumped as soon as "rockstar" will find another flashy term where he can gain more "ninja" points.