Syfy cancelled Stargate SG-1 because the network was pivoting to putting more effort into their other shows like Eureka which had a more general appeal. The writers snuck this cryptically meta exchange into S10E18 “Family Ties” poking at the network for how they felt the series was being mistreated.

In my opinion, it was a mistake to make seasons 9 and 10 of Stargate SG-1 instead of their original plan of making it a spinoff called Stargate Command. If they would have started fresh as (technically) a new series, I think it would have been overall better for the long term health of the franchise.