Well, I see your argument, but I'm sure there was a lot of "roughing it" in King Arthur's time. Really if I had a choice I think I'd prefer to live in the wild west. Sanitation, technology, and all were far advanced from late classical pre-medieval Britain, no matter how it may seem.
I have always thought of DF as less a game and more a fantasy world simulator. Sure, there isn't any magic, but all the tropes are there, elves, dwarves, goblins, kobolds. And now we're going to have werewolves and vampires, too, so that overplayed, soap opera-y genre can be included as well. If you were being uncharitable, you could call it fantasy-medieval Sim City. But more than that, a game you can WIN. DF cannot be "won". You just survive until something goes horribly wrong, by the inexperienced through oversight (oh crap, I didn't wall off the entrance to the caverns) and by the experienced through cheapness (oh crap, the forgotten beast that my legendary, spoilerite wearing badass army that took me 14 hours to build just took down in 2 seconds has a syndrome that slowly kills and infects everything).
I think in our current cultural background (I'm a US citizen but I'm sure this also applies pretty much everywhere) the most recent example of "colonization" is the American wild west, and we have kind of romanticized King Arthur times as being all about glorious battle, Roman Legions, mystical quests, magic, and hot faerie folk, but be aware that in the "real" King Arthur times colonization was happening all over the place. It was dirty, it was survival, it was squalor. Closer to DF than you might think.