These were manufactured for Dish back in the "chicken or the egg" days of HDTV: While there was some HD content, hardly anyone owned nor would invest in the VERY expensive HDTV of a decade ago--OR--no affordable HDTV's because there wasn't enough HD content to create sufficient demand for HDTV economies of scale to bring down the price of the HDTV.
In Dish's case, they had invested in HDTV content as the future, but they weren't getting enough HD subscribers at the rate they would have liked. So, Dish figured if they can find some way to get an HDTV into their subscribers home at a low enough price, this would allow them to grow the HD subscriber base and get a greater return on their investment in the HD content as they were the first MVPD to invest in HD in a big way.
Sony was to have been the manufacturer of the Dish branded TV's and had considered Plasma, but Plasma was too flaky at high altitudes in those days. So Dish had the Thompson Corporation (owners of the RCA brand) manufacture the CRT HDTV's as a Dish branded product. Being a Thompson TV, they were significantly lower in retail price than the competition, which made it appealing to those who wanted to view HD content, provided they subscribed to Dish.
The market finally changed and HDTV's soon saw dramatic price drops with improvements to the display technology along with more HD content to justify the expense to the consumer to buy an HDTV. The tipping point had oocured, and the whole idea of providing a Dish branded HDTV became unnecessary as Dish's intentions for such a TV was short term only, never for the long term, just long enough for the tipping point to occur.
I understood them to be buggy and not that great of PQ compared to the competition of the day, but they were a lot LESS expensive and many seemed happy to enjoy HD content. But, there were Thompson manufactured (Thompson branded some of their own TV's as Thompson and others RCA as they owned the RCA brand), among the cheapest TV's on the market then and not know for high quality.