The co-creator of Stargate was interviewed about it and said:
>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.