Sure, but 90%+ of people who buy Mustangs will never race them on a track. So does that mean Ford should start offering a Mustang version of the Fusion?
If OP is looking for a truly off-road capable SUV, his best bet is to hold out for the 202x Bronco (whenever Ford gets around to announcing something more official than a photo of some boots and a backpack in the woods). But the jury's still out on what type of vehicle the new Bronco will really be.
One's thing's for certain though: The truck OP wants (Expedition + Raptor) is a pipe dream.
Your analogy doesn't hold water. Mustang is a model while Raptor is a trim level. Some people can already buy the Ranger Raptor. No reason they cannot do the same to the Expedition. And many people are hoping for a Raptorized version of the Bronco when that comes out.