Earlier quoted context omitted.
Some level of programmability is probably worthwhile although you can get a lot of the same effect by manually turning the thermostat up and down which I do a lot anyway. And if I didn't have a programmable thermostat I might well spring for the extra dollars on the Nest if only for the cool factor. As it is I have a programmable thermostat that mostly works just fine. A lot of people are likely in that situation. I'…
Yes, because the average person has the willpower to go walk over to their thermostat all the time -- especially when they leave / come home. Not a chance.
Turning off your heating/cooling apparatus is the most natural thing for people in Japan.
Don't people turn their lights off in the us?