I think it's more to do with the 'democratisation' of television.
It wasn't so long ago that you had to have come from Oxford or Cambridge Universities (or have a background in Shakespearean theatre) to be in TV comedy.
The Goons, Monty Python, Peter Cook & Dudley Moore, Rowan Atkinson, Smith & Jones, Fry & Laurie all came from that avenue. These days it's almost unfashionable to have that background.
The other thing is that taboos have fallen away. And to equate that with falling standards is quite wrong.
Compare two political comedies - Yes, Minister and The Thick Of It. The latter is absolutely stuffed full of brutal swearing. But I think you'd be hard-pshed to argue that it's of a lower standard than Yes, Minister. It's critically lauded and merely reflects our acceptance of realism in comedy.