I think there's a general rule that once you add certain things to a product, it's no longer that product. Let's take a human being for example. If you add wings to a human being, they aren't a human being with wings, they are an angel (or devil, depending). The same thing with a sleeping bag. It's a sleeping bag because it's a bag. You don't call it a jacket without arms. If that's the case, why is this even classified as a sleeping bag? This is just a comfy onesie.
Don't get me wrong. This is exactly what I want the next time I go camping. What they really need is a crotch hole though. I want to be able to walk out of my tent and go whizz outside. What's the point of this mobile-tent if you can't pee freely?