Have you ever thought that most broadcasters can't 'afford' or justify moving to HD, because so many people are still using CRTs? Who breaks this cycle? Sky had 1 million HD customers, but it's still only a small fraction of the number of TV sets in the UK.
I doubt broadcasters would ditch SD and move over to HD in a hurry as it costs so much to produce HD content (new sets required, more expensive cameras and post-production).
I go back home and watch an old CRT and still think it has excellent PQ. However, I come back here, power up the PS3 and one benefit of a large 1080p screen is that they can be played and viewed in their intended 'glory'.
The limiting factor to the spread of HD isn't the number of CRT TV's out there. In technical terms it is simple to provide an SD stream of the same program. The limiting factors at the moment are availability of HD Content and bandwidth.
CRT TV is still the best option for most day-to-day TV watching, even though in the longer Long term CRT is dead in the water, which is why CRT TV's are exclusively low-end budget models these days. We will all be upgrading in the end, but I am happy to wait for now.
Simon