I drove a rental that had collision detection in it. Three or four times, it suddenly slammed on the brakes for no discernable reason, and with no regard to how close/fast traffic behind me was moving. I had to pull off, download the manual, and figure out how to turn it off before the car killed me.

One of the most important things in safely operating a vehicle is using gradual, predictable movements. My car braking without my input makes predictable movement impossible.