There should be a very clear distinction in responsibility between the automated systems and the driver. I think the danger presented by some of these systems is that they blur that line and lull the driver into the sense that the automated systems are responsible for more than they are intended to handle. It's hard to maintain alertness, awareness, and readiness without an actual need. So, if the automated system correctly handles steering and speed control to maintain lane position and a safe following distance, it's easy for someone to start leaning more and more on the automated systems instead of being constantly prepared to intervene.
By that logic cruise control is totally useless drivle also because you have to still have to pay attention to needing to slow down, speed up, or stop.
Cruise control requires the user to maintain positive control and awareness. It maintains a given speed, but still requires you to be directly involved in driving the vehicle at all times or you will crash in short order. When we're talking about systems that can handle all direct control (speed, steering, obstacle avoidance, etc.) of the vehicle in certain circumstances, it is hard to maintain that mindset. If everyone is responsible, no one is responsible.