Yes but lots of people don't know what streetpass is, and they're like huh, how does that work, what is that? Where is the model home section?
At the developers discussion of AC they exactly mentioned it. If you have a 3DS you most likely know what Streetpass is, they cant waste time in a ND explaining basic functionality of the 3DS itself. Plus, if they say "Animal Crossing: Jump Out uses Streetpass. When you pass people while your 3DS is in sleep mode and they have Animal Crossing for 3DS, their home will be put into your model home section in your town." Not that difficult explain or comprehend if you don't know what Streetpass is.
Point is: Streetpass does not take 20 minutes to explain from what we already know.