Quoted from Civ V manual - "We hope youre proud of yourself, you big bully!"
The manual is riddled with childish comments and notations, since when has this game been targeted at 8-13yr audience? Most of the players I seen on Civ Fanatics are adults.
I don't find it amusing and i've seen it in the Civilopedia too (read:GDR). I don't see the point in it, I think most people would just appreciate some professional writing.
TL;DR - manual written by idiots?
I agree. Seeing mild swearing, mistakes and crude abbreviations ('em instead of them) seemed pretty unprofessional to me. Makes me worry about the general dumbing down of society when that sort of thing gets accepted.