I don't know why, either, since this would presumably be very easily debunked.
For a representative example, see how bad Mercedes’ latest and greatest E-Class w/ Drive Pilot is: http://www.autofil.no/936897/hands-off
It’s damning. And that is the one they advertised as being “self-driving”. That’s the best Mercedes has.
This review compares more of them: http://www.caranddriver.com/features/semi-autonomous-cars-co...
The best of non-Teslas have at least twice as many autonomous mode disengagements (i.e. they suck at the lane keeping job). They specifically call out Model S for being the only one that can keep in a lane without wobbling like a drunk driver. None of the “old” car manufactures can even get that right, let alone anything more.
So yes, on paper all these components exist for 3+ years and are nothing new. Exactly like smartphones existed before the iPhone did — remember those?