This is only true with false-negatives. A false-positive (say, on a pedestrian-free, controlled access highway) could easily be actively harmful if it causes abrupt changes in vehicle behaviour that would not occur if a human were in full control.
Maybe in the eyes of the law. If pedestrian-detection-equipped vehicles cause more deaths, however, it is quite relevant.
The systems are not reliable yet. Fortunately humans are not totally reliant on them yet either so humans are still effective as a safety backup.
The trick is to make sure the crossover point (when humans become so reliant that they are ineffective safety backups) comes after the system becomes highly reliable. Unfortunately humans are already unreliable to begin with even without AEB, so we are just going to deal with a few incidents from autos, both those without AEB, and, until it becomes perfect, those with AEB.
Too late, we're commenting on an article about them failing in common scenarios.