This makes sense even for people who *aren't* total idiots. What do you do with stock apps you don't need? You shove them off into a folder on the last page of your home screen all to themselves and never look at them again. Is it that hard to believe someone might have done that when they first got an iOS device, and forgot they was there by the time (possibly years later) they wanted one of them?
Now, that's unlikely with a web browser. In that case, you have the opposite potential problem: someone new to Apple who is used to looking for IE, or Firefox, or whatever, and doesn't even know what Safari is because they've never seen it before. "App Store," though, is obvious in its purpose; it makes sense that someone who didn't know that Apple's browser is called "Safari" and looks like a blue compass, not because they're stupid, but simply because they've never run into that information before, would try searching there for one.