Wrong end of telescope?

So the penalties for using a hand-held mobile 'phone whilst driving are to be doubled.  Is this the right approach to the problem?  As I understand it, the technology exists to make using a 'phone in a car as safe as can be (as has been mentioned in previous posts, nothing is ever 100% safe), so why are we not requiring the makers of cars and the manufacturers of mobile 'phones to construct their products so that this technology is built in and available to all?  Is it just easier (and more profitable) to clobber the motorist?