You're looking at the problem from only one perspective: injury. It is true that this system offers no protection from injury for occupants of the automobile, but any time you strike someone or something, there's the additional matter of liability.
If a system like this is widely available, and it proves effective, then there will it will provide the benefit of reduced injury. Reduced injury means lower medical bills for the injured and lower settlement payouts.
Insurance premiums are tightly modeled. Lower risk and incident costs mean lower rates. That's one potential benefit to the purchaser.
You also have to consider regulation. Humans are poor judges of risk. There was a time not too long ago when consumers would choose "cheap" over "safe" if given a choice. I don't mean to say that consumers would walk in to a dealership and say, "Give me the cheapest car you have, safety be damned!" I mean to say that car manufacturers would say, "Oh yeah, of course it's safe," and consumers would take their claims at face value. That proved to be a poor choice.
Enter government regulation. At some point, it became clear that automakers and consumers weren't going to make cars sufficiently safe on their own. The first steps in safety were things like mandatory fitment of seat belts, then compulsory wearing. Airbags followed, then ABS.
Now we're seeing an increase in regulations related to pedestrian safety. There are already some pretty significant laws on the books in the EU related to pedestrian safety. Car and Driver, of course, takes the perspective of how this effects automobile design:
http://www.caranddriver.com/features/taking-the-hit-how-pede...
Volvo has a pretty long history of pioneering safety systems that are later made compulsory by legislation. I suspect we may be seeing the same thing here.