IMHO, the reason why the ViewSonic/T220 wasn't adopted in wider use isn't because of the reasons you listed above. It was because very few graphic cards could push that many pixels back in 2003.
That, and lack of operating system support for high PPI displays. A friend of mine has his PC hooked up to a plasma TV, and it's absolutely astounding how poorly Windows 7's UI element scaling "feature" works, in 2013.
A plasma TV has really LOW PPI... Like it's 50+ inches with only 1080 pixels down the screen... That's like a factor of 10 worse than retina displays...
No kidding. The effective PPI (number of dots that make up the display / size of the image being projected onto your retinas) of a large TV viewed at a distance is pretty high, though, so both "retina displays" and large, low-resolution TVs viewed from a typical distance require large fonts etc. to be legible.
If you could afford the monitor the graphic card would hardly be an issue.