Looking at it from the OEM's point of view, I can see their reluctance to allow it, given that they're on the hook to comply with ever more ridiculous standards of economy and safety and are relying on more computer control over every vehicle subsystem to do it.The villain here, as it almost always is, is the good ol' .gov, who has issued instructions to automakers that border on ludicrous.
I don't like it one bit, but it looks like the wave of the future. (I also think that those who say we're closer to the era of self-driving cars than we realize are probably right. *checks watch* Thank god, only twenty more years left. ;) )
This is how we've wound up with Ford pickup trucks built out of aluminum and sporting V-6 powerplants with twin blowdriers and direct injection that wouldn't look out of place in a full-on open wheel race car not all that long ago. We're getting to the point where my turn-of-the-millennium, OBD-II-compliant Bimmer has more in common with the carburetted vehicles I drove in high school than it does with the newest stability-control-having, Wifi-hotspot-equipped, "mild parallel hybrids" rolling off dealership lots these days.