I don't see what fucking language you're talking about. Joke aside, I think this is just part of the author's humor, it has nothing to do with being arrogant.
That fucking language was quite mild. Past versions of Linux (don't know if it's still there) used to have a quote from "Heathers" in a comment: "Fuck me gently with a chainsaw", as well as non-quote swearing like "fuck me plenty" and "fuck me harder".
init/main.c:
/*
* Tell the world that we're going to be the grim
* reaper of innocent orphaned children.
*
Some software development subjects are best not discussed in front of ordinary people, but it's hard to not make fun of it when you're dealing with a daemon that's not properly reaping it's zombie children...
Though when searching for a reference (http://www.ohohlfeld.com/linuxfun.html), I found this (non swearing) gem:
Some software development subjects are best not discussed in front of ordinary people, but it's hard to not make fun of it when you're dealing with a daemon that's not properly reaping it's zombie children...