They released a video a month later (3 weeks ago) with a much more challenging route:
https://www.tesla.com/videos/autopilot-self-driving-hardware...
https://www.tesla.com/videos/autopilot-self-driving-hardware...
So either the problem in practice is much harder than a simple video can show, or something else is up.
Though, I think the real issue is that google wants to go straight for L5 (meaning 100% automated, and you can remove the steering wheel). As compared to an L4, which is more like 99.9% automated, but you still need steering wheel for those rare edge cases.