A lot has happened since then more than 50% of the world's population now live in urban environments. I'm from Africa and electricity is more prevent than water, moreover cell reception is more prevent than electricity, cell reception is ubiquitous and governments are spending a lot of printed money to bring electricity to urban areas, I can't see your vision because it conflicts with some things I see that are tangent to your circular view of the world.
You focused only on the less salient point that I made. My point is energy efficiency for excess heat is not a target market in the developing world. Severely resource constrained people don't heat their homes, they wear extra clothing instead. They use cold water for the most part, or boil their water in a pale, or us a hot water heater at the shower head which only runs a few minutes per day. Go take a look around your area and confirm it for those who are not wealthy enough that the savings is irrelevant to their core opportunity costs. For those who can afford to heat their homes, the opportunity cost is only going to make sense for a fraction of them. It is an incremental target market, not a huge sweeping one.
Please make sure you understand my point about tsuris and opportunity cost before retorting me.