It depends on what kind of masses you choose to emphasize. There are many kinds of masses. Some masses earn US$100K or more per year. Some others earn US$100 or less per year. You said you know lots of people that use only SD. You could have just chosen to say you know lots of people that can make use of 4K right now instead.
Real videophiles need not wait for 4K X 2K TV. They could have bought one or more units long ago.
In 2007, 1080p and Blu-ray were not exactly early. Blu-ray recorders were expensive for the mass, but 1080p was common enough in 2002.
LCD was not something "fairly new" in 2007. Plasma-based TV sets were cheap and everywhere years before LCD. I had a LCD TV capable of 1080p in 2003. I do not mean every home in the Congo Basin by everywhere.
Yah the movie/hardware companies seem to really want to push 4k.
The movie companies have been the very force most reluctant to delay the introduction and mass market adoption of anything beyond HDTV and Blu-ray. Whether they gain or lose because of added standard better than existing ones is difficult to tell, but it's plain they don't like anything new.
The needs and desire for higher standard were largely from engineers and entrepreneurs in Japan and movie consumers in the US.