The show was a mid-season replacement on CBS. It aired for the first time on June 16, 1976, and it was only four episodes long initially. (The clips that feature Sonny Bono, which are probably on youtube, were from the first episode. Mackenzie Phillips, Ed McMahon, and Joey Bishop were on during that 1st season. David Letterman, Muhammad Ali, and Betty White were on in later episodes.) Anyway, the show was picked up again for a little while (Michael didn't want to do it, but he signed on again just the same). The ratings plummeted, and the show was officially cancelled in January 1977. The last show aired in April of 1977 at 70th place in the ratings.
So, basically, I doubt it's got a big enough following for CBS to spend money on to convert to DVD ( I could be wrong, but that may be why). I do like the Youtube clips, though. However, I only like them because I'm a big Michael Jackson fan! If I wasn't, the show wouldn't be worth watching. It's just not that good, sad to say (but MJ aparently agreed with that, too
)
*most of this info was obtained from
Michael Jackson - The Magic and the Madness, by J Randy Taraborrelli, pages 179 - 183 (Chapter 12)