I saw this coming two years ago. It had a great premise, but around the third season, the fan adulation had gotten to everyone's heads (it was affecting SG-1 also, RDA was wise to get out when he did), and they started turning every character into indestructable supermen and got too smug about themselves. It wasnt Stargate anymore to me.
Then the show got even sillier when it became a victim of "Daniel Jackson Syndrome". The casts started changing frequently, and things got really desperate when they had to pull in The Replicators, Tapping and Picardo...Atlantis no longer stood on it's own, it looked like SG-1's handicapped sister show needing as many crutches as it could to stay releavant. It made the abysmal animated series Stargate Infinity look like a better show in concept (which it was, it was just executed badly)
SG-1 was popular because it was a great throwback to syndicated fun and was about down-to-earth military trained people exploring worlds and going through personal journeys. We saw where they lived, who they loved, what they did off-duty...Atlantis had NONE of that relatable content because it was set on alien worlds and cut off from worlds...and the city's ability to fly completly down-graded the importance of the Stargate.
I don't watch spin-offs that think that there Star Trek, instead of what they ought to be.