I agree, but since movie theatres are not doing that great... the market for 4K as a whole is tiny at best and not likely to grow for many years. Realistically, most people would benefit a lot more from correctly optimized 1080p with less compression.
Even that is ignoring the realities of the marketplace. 1080p content is still not near 100% penetration of "HD" content delivered to homes via cable, satellite or online - so it's either 1080i or 720p. And when it is 1080p, it's compressed to oblivion to fit more channels in the fiber, less bw cost to deliver the video, etc. But you don't hear many people complain, it's only the movie buffs and early adopters.
What I'm saying is that we're stuck with HD (and "HD") into the foreseeable future - 5 years, more likely 10 or even more.
Oh, and let's not forget that you won't get benefit from higher-than-1080p resolutions in a home setting until you get a BIG screen - and that's even more costly, as it requires not only the expensive set/projector, but also a big living room (costly).
Remember, these are the people who think 128kbps MP3 is just fine.
48 fps on the other hand is another matter. Not sure how many current HD TVs are compatible with those streams, but it might be the next big thing rather than more resolution.