4K is about the number of pixels. 3D is entirely something else unrelated to anything.
So you agree 4K will succeed 1080p HDTV and Blu-ray? Then, you agree 4K TVs will become widespread.
So why are you insisting there will be very little contents for 4K?
Really? Are you sure contents providers were "a lot more invested" in providing HD contents?
The fact is that it took very, very long for analog TV to spread and the contents compatible with those first-generation TV sets to become available at low cost. The time to market for the first color TVs and color contents was very much shorter. It took even less time for first digital TV and digital programming to be standardized in Japan, the US, and Europe. For SD to evolve to HD, it took some more years and most of the delay had to do with regional patent wars since that was all about money and media influence between Japan, the US, and Europe, and also between left and right, between North and South, between every competing groups.
What's happening is complex enough. Acceleration in technological research and development, media fusion, competition and convergence between home electronics and computers, and between traditional industrial centers of production and consumption of media and all kinds of new media that cannot fit into traditional categories, shift of power, shift of regional basis of production, accumulation of copyrighted and pirated cultural contents, these all contribute.
Many of the current 4K TV sets and 4K computer panels (for desktops and portables) are already at least as cheap as the first TV sets and the first HDTV sets and the first flat panel TV sets during the early introductory periods. Nobody is forcing you to buy a US$4,000 4K TV before the end of 2013. What is apparent is the rate of adoption and the speed of conception to R&D and to mass production and mass marketing regarding 4K have been overwhelmingly successful. It took more months than original plans to commercialize the first-generaiton OLED 4K TVs, but it took relatively a very short period of time for such things to appear considering only Samsung was really heavily investing into OLED. The very term 4K was not on the web frequently several years ago. HDTV or something like that first appeared years before I was born. It took practically two generations for most developed European nations to finalize their own HDTV specification.
Blame your own politics rather than the electronics industry. This time, it won't be that easy for the entertainment industry and reactionary governments to delay as long as possible. 4K is just the beginning.