Re: People don't want it.
"Surely logic would suggest that it's because most people can't tell the difference between the two "HD" resolutions* that 4K is needed to really boost resolution to make a visible improvement?"
No. It's to do with the fact human eyes are limited in the amount of detail they can detect at a certain distance. For any given screen size there is a particular distance where the eye can begin to tell the difference in detail between different resolutions.
This page will help explain it: http://carltonbale.com/1080p-does-matter/
As an example, if you want your eyes to be able to pick up enough detail to tell the difference between 1080p and 4K on a 50" TV, you'd have to have be sat less than 7 feet away from it. Most people (in the UK at least) will find the ratio of distance vs screen size doesn't work for their living room, hence 4K is pretty pointless as a mainstream home technology.
4K enthusiasts can argue all they want with anecdotal evidence that they could tell the difference at 20 feet away. They really can't, it's human biology.