I had a professor once who specialized in human factors design in cockpit safety. Her view was that it was pointless to blame anything on "pilot error" because if the plane let the pilot screw up it was a flaw in the design of the plane.

That's a good way to view any problem having to do with people. People are the same as they've always been--it's ludicrous to think that they're intrinsically any lazier or have less self-control than people a generation or two ago. If they're a lot fatter than prior generations, then something external must be different. You're never going to fix people, so if you want to solve the problem you have to focus on those external things.