No, it's not a purely single variable optimisation. If this system (and let's be honest, we're just talking about Tesla here) cannot avoid hitting an object tha

No, it's not a purely single variable optimisation. If this system (and let's be honest, we're just talking about Tesla here) cannot avoid hitting an object that every driver should easily see, then it's not fit for purpose. The reason being that people take action based on certain assumptions about what drivers will do. If a pedestrian steps into a road to cross when an oncoming car had plenty of space to both see and slow, then it's not ever acceptable to hit the pedestrian. This is a normal urban interaction.