I think it was a very clever show and from story point of view, it still had lots of possibilities. I loved to watch it.
But honestly, I didn't find it"too liberal" but rather too idealistic. It painted a world where a comedy TV show is still the main program of a TV channel, where the staff works together smoothly, where even the executives of the network aim for quality and for profit. Oh, I agree with Sorkin, this would be a nice world to live in. And I think he just imagined what would happen to a show if it were handled like this. And reality followed in a way his fantasy: S60 got the chance. A whole lot of chance from the network.
But the audience didn't watch it because it was too different from that they used to and from what they experience. Yes, there is a strive to put yourself into mystery world when watching tv but also, you'd like to personalize with the characters. And here, all characters were too good. They all lived up to a quality standard an everyday person can't because ... Because of several reasons but probably lazyness. The lazyness which sometimes helps us to created wonderful objects like cars or washing machine, sometimes lets us down but not forcing us to think.
So these characters were way from us and far from reality just like the surrounding environment of the show. There was nothing that related to our life.
BTW: the sketches. I had the feeling that they weren't funny on purpose. To be honest, the remaining sketch shows aren't any better. I found a beautiful irony in this.