The purpose of air conditioning in comfort -- so arguing that people can make themselves slightly less comfortable by doing something different is moot. It's even more energy efficient to not run the AC at all so why argue about vent position?

I don’t think they are implying that. If someone’s preferences are based on metric A, and another method provides better results with regards to metric B, even if metrics A and B are correlated, this needn’t be a reason for the person to prefer the proposed alternate method, because the current method may still provide results with regards to metric A.

Telling someone that tomato is a more vibrant red than chicken, will not compel them to prefer the taste of a tomato to the taste of chicken. (In this example the “correlation” bit doesn’t apply, but, whatever.)