The main problem is resolution.

* The resolution of the TV controls the crispness and detail in the picture you see.
* The resolution is determined by the number of pixels on the screen.
* An analog TV set can display 525 horizontal lines of resolution every thirtieth of a second. In reality, however, an analog TV displays half of those lines in a sixtieth of a second, and then displays the other half in the next sixtieth, so the whole frame is updated every thirtieth of a second. This process is called interlacing.

So the worst computer monitors you can buy have more resolution than the best analog TV set; and the best computer monitors are able to display up to 10 times more pixels than that TV set. There is simply no comparison between a computer monitor and an analog TV in terms of detail, crispness, image stability and color. If you look at a computer monitor all day at work, and then go home and look at a TV set, the TV set can look very fuzzy.

The drive toward digital TV is fueled by the desire to give TV the same crispness and detail as a computer screen. If you have ever looked at a true digital TV signal displayed on a good digital TV set, you can certainly understand why -- the digital version of TV looks fantastic! There is no comparison. With 10 times more pixels on the screen, all displayed with digital precision, the picture is incredibly detailed and stable.
-- How Stuff Works

Hi-Def Television: '06 HDTV Sales to Outpace Analog
Oct 31, 2005 -- Daisy Whitney -- TV Week

Sales of high-definition TV sets in 2006 will for the first time outpace the number of analog sets sold, according to the Consumer Electronics Association, which predicts that retailers will sell 12.1 million analog sets and 16.3 million HD sets next year.

S.1932
Deficit Reduction Omnibus Reconciliation Act of 2005 (Engrossed as Agreed to or Passed by Senate)

SEC. 3005. DIGITAL TRANSITION AND PUBLIC SAFETY FUND.
(1) Not to exceed $3,000,000,000 for a program to assist consumers in the purchase of converter boxes that convert a digital television signal to an analog television signal, and any amounts unexpended or unobligated at the conclusion of the program shall be used for the program described in paragraph (3).

***this bill cuts $5.7 billion from Medicare and $4.2 billion in Medicaid, while the House bill would chop $14.3 billion in student loans, $4.9 billion in child support and $844 million in Food Stamps.

*** the House plan would limit subsidies to $990 million.

Environmental Protection Agency - Office of Air and Radiation

Summary of Rationale for Suspension of the ENERGY STAR® Specification for Set-top Boxes – July 2005

"The ENERGY STAR specification for set-top boxes was officially suspended on February 2, 2005.

"When current market conditions change and become more conducive to having an ENERGY STAR specification for set-top boxes, EPA will revisit the program and consider developing a new specification for these products."