Has anyone, who complains about "low production values", seen an episode of Not The Nine O'Clock News recently? Because some of it was really f**king ropey. And producers, directors, writers etc, know that they could make a varied sketch show like that again - but that they'd never get enough budget to do so without getting ripped to shit by critics.
So yeah, it really comes down to money.
Re: His Own Devices' comment about lack of satire, we've had a broadly left-leaning Labour Government for most of the last 15 years. In a media populated by equally left-leaning types, it's really no surprise that the art of satire has all but been allowed to die. People like the 10 O'Clock Live team are attempting to bring it back, but you only have to watch an episode of the show to see how much damage that deacade+'s vacuum has done to the art.