There are so many reasons to change this feature after the fatal car accident, but the reality is that there are still many variables at play on many of the roads today. My biggest question around these self drive cars is around the response times during an emergency. Sure a car can do a lot with electronics, but how will it handle excess loads of work and data as it drives? I think adding in a radar or maybe even a secondary measure helps to cover the bases.
Even with all this said, I must take my hat off to Tesla for developing cars with this auto pilot feature, it takes a lot of work and challenges to come up with something like then and even more to then put it into the commercial market. They have handled it very well and spend a lot of time making sure that they fix and adjust things if there are problems.