I love the example of the muppets because they align with something Steve Guttenberg likes to say — namely, "abandon the quest for perfect realism," or words to that effect. What we want is something that pleases us. We might call that "comfortably real."
Your post made me consider that there are lots of ways a system can be comfortably real, and that involves (as you put it) "alignment with real physics and real human motion." Another way of describing such alignment is "natural" or, more humbly, "the way I move, too."
Your post also made me consider that there are things a system does in obvious and overt ways which also create other non-focal aspects. We could call these the "fringe" or background that makes us feel at home. None of this is unusual for an interior decorator, who understands that colors and placement of objects — however much we’d call them environment or background — are critical to making a house feel like a home.
What we may be making explicit, here with audio, is that same kind of thing. Music that makes us feel "at home."