As a person who has long used a PC attached to a TV as what it's now called a "Media Center", I can say the text quality on a CRT television is absolutely horrible, totally unusable for browsing or programming. Games, movies, sure. But not anything that would increase the computer literacy of the masses.
This depends completely on what you're displaying on the TV and how.
I used to be an Amiga user (first the A500, then an A1200 with a 68040 card). I've spent numerous hours programming demos and software on Amigas using a TV as the display. During the first few years the TV was an old 14" one and the signal was RF modulated. After that I used a 21" with an RGB SCART signal. On the desktop (Workbench) I used a 60Hz-PAL interlaced screenmode (640x512 with overscan, can't remember the exact size) and when programming a screenmode without interlace (640x256).
The image was clear and fully readable; the interlacing naturally does make it a bit nasty for things like text editing but works just fine for the desktop. No, I did not lose my sight either and didn't have to start using glasses. :) Instead, I learned a sh*tload about programming, both low level and high level, and hardware. This knowledge has helped me a lot in my current job as a PSP programmer. I also browsed the web and read my mail just fine, too.
With proper font, UI, hardware and screenmode choices a CRT TV is certainly a suitable display. Don't let the typical PC TV Out experience fool you. It's been done well ages ago.
(Hint: ditch the interlace when possible. Both fields do not need to be drawn - it's enough to draw only the even ones and you'll get nice true 60FPS framerate as well. Also remember that the TVs are much slower than monitors - 60Hz is enough and won't give you a headache!)