By "pass or fail" I meant to point out that our appliance scored both A++ and F at the same time, to reiterate the point that what could be a simple and useful guide can be confusing in practice.
If you provided evidence of how much people value energy stickers from a 3rd rate slideshow from a defunct one-person consulting firm, I would consider it weak evidence, but better than no evidence. But public opinion is not as important as the real outcomes of the program.
The "vaguely related" quote is in response to your statement "at least that's the intention" behind adding QR codes to energy stickers. If the ultimate purpose of the program is to save energy, then we should judge it on how effectively it saves energy, not on intentions. I think Friedman is correct in observing that public programs are often judged by intentions rather than outcomes. Whenever I research a government program, I find gaps between intentions and results.
Women, and Infants Children program
Intention: "safeguard the health and well-being of the Nation’s children"
Result: The program is dominated by three corporations that make infant formula. Subsidized infant formula relieved malnutrition, but also reduces breastfeeding, harming child health.
Paid Maternity Leave
Intention: "to balance the demands of the workplace with the needs of families, to promote the stability and economic security of families, and to promote national interests in preserving family integrity."
Result: A 1% payroll tax is deducted from all California employee income. Some of this is used to replace income for new parents on leave (affluent parents are more likely to participate). Three-quarters of people in low-income groups do not know that the paid leave program exists.
Clean Air Act (suggested at my request for "an example of regulation done well")
Intention: clean the air
Result: The air is cleaner, but costs of the program were enormous, and government authority worked closely with industrial interests for decades to promote and defend leaded gasoline, now recognized as one of the most harmful atmospheric pollutants. Several cities banned lead for health reasons in the 1920s (against the advice of the Surgeon General), but the EPA did not enforce a national ban until the 1970s.
As to your questions, I do think it is fine for people to make some effort to find legal ways to save on their taxes, and I also think people shopping for appliances would do well to become informed about energy and water consumption. These activities probably pass a cost-benefit analysis, especially for people who enjoy being informed. As you point out, an hour or two of research can pay off with years of savings. (If you want to prioritize one or the other, I guess it would be the one with the greater expected payoff per hour of research.) I question whether the energy stickers are sufficiently effective in assisting this research to justify the considerable energy used to run the program.