Earlier quoted context omitted.
Without being able to determine future road conditions then automatics can't guarantee being in the "right" gear for the up coming section of road. Be that due to traffic, grading, weather, banking, sharpness of corner etc. My go to example is the insanity of junction 15 of the m8, that loop onto the west bound motorway is a 270 degree corkscrew rising 30 feet with a diameter of 55 yards onto a 5 lane motorway where…
Or just buy a Nissan Versa today: http://www.edmunds.com/fuel-economy/five-myths-about-stick-s... Manuals have better fuel usage then automatics is a myth for recent cars, no fancy self driving needed.
Now in a high-end car with a sequential gearbox this is different, but for a small town car when you'll be doing a lot of starts and stops you'll see the losses on the hydraulic coupling.