Increased efficiency is a large part of achieving a carbon-neutral energy system, and this program is a huge part of that.
This is also a key part of adapting to climate change. In a time when the ability to cool a home and keep it cool will become ever more important, control of air flow and energy flow is key. Weatherized homes not only save money, they are better able to withstand drought, heat waves, storms, cold, and air pollution.
This is one of those cases where we can simply do things better than we used to, and at a pretty low price, all things considered.