Engineers, more than anything else, don't like it when you piss on their leg and tell them its raining. Musk's statements here are Ballmer-esque marketing doublespeak: We've been focused on "safety" to date [don't mind that our cars run themselves into concrete barriers], and will roll out "full autonomy features" in the next software update [don't mind the NTSB report that shows that our technology is a glorified version of the lane-keeping everyone else is already doing].

I think a lot of the reaction on HN is the result of people simply realizing the large delta between what Tesla claims to have, what people thought Tesla has, and what it actually has.