As far as I understand it, the movies were actually very successful, but there was some kind of internal politicking or studio issue and they just didnt continue.
Interestingly, he also talked about the need to appeal to an audience outside of the existing fan base, quite relevant to the current discussion:
>If you just try to hang on to the viewers you have and the numbers are going down, they’ll eventually go down to the point where the network and the studio will say, “OK, we’re done.” That’s what happens. That’s definitely what happens.
>The only thing that is blocking the SG-1 movie or the Atlantis movie, the only thing, is the fact that the direct-to-DVD market has gone away
https://web.archive.org/web/20101001085140/https://tvdeathra...
Interestingly, he also talked about the need to appeal to an audience outside of the existing fan base, quite relevant to the current discussion:
>If you just try to hang on to the viewers you have and the numbers are going down, they’ll eventually go down to the point where the network and the studio will say, “OK, we’re done.” That’s what happens. That’s definitely what happens.