He also mentioned about when O'Neill was a general, and his overall apathetic attitude, like the actor didn't even want the role.
It was never serious, but at the end they clearly stopped caring.
However O'Neill was made a general because the actor didn't care. He wanted to leave the show and spend more time with his daughter. They made him a general so he wouldn't have to come in and work as much.
And they had random Earth episodes because they were cheaper to do than "alien" episodes.