Human drivers kill ~260,000 children a year. The bar for robots is low.
In other words, it probably only takes an accident, not even culpability, to get demonized.
The fatality rate in the US is around 30k-40k every year[1].
[1] - http://www-fars.nhtsa.dot.gov/People/PeopleAllVictims.aspx
http://www.wolframalpha.com/input/?i=deaths+in+traffic+per+c...