I never understand situations like this. Yes, absolutely, mapping is not a combat skill, but it's not a bad skill either. You can just "buy a map" to get the same information? What about dungeons? Do those maps really have all the up to date information in them? Not even close. Like, seriously, I understand what the author is trying to imply -- they needed it to be a skill that they can make fun of but then show is actually really damn good and can be used to good effect, but the problem is everyone should already know this.
Even if you ignore his pessimistic attitude about his mapping skill, other people seem to imply it's pretty low tier too. Only a fool goes into a fight without the best information they can get.