You are right that there are not enough NPCs. I simply did not have enough time to add more than there are before the release date. Most buildings are also left unenterable, and most enemies have a quite empty attack pattern for the exact same reason. I have already added more in the working version.
That being said, considering that the map is as small as it currently is; I wouldn't agree that the number of NPCs are a big issue when it comes to the language in this game. After all, you can at any time refill your Mead of Poetry. It stands to reason that the language will be more pronounced the further you move away from the point where you fill up on the Mead, but the game is simply not long enough yet for that.
That being said: there should be more NPCs than there are. But not because of the language, just because it would fill up the world more.