To give some perspective about the BBC's innovation, 'All In The Family' was the BBC's 'Till Death Us Do Part', made by US networks for US audiences, (as usual US TV
networks greatly toned down language and content), more recently 'Coupling' had the same treatment, the latest in a long line of such adaptations, again much of the humour of the original has been lost by the insanely patronizing attitude of the major networks towards their audiences, is this due to advertising pressures?
However advertisers seem to have much less influence over commercial UK channels, Channel 4 has advertising, ITV
produce a huge amount of lazy, formulaic programming, this is something the BBC is sometimes guilty of too, but much less so, the best channel for me at least is BBC2, often interesting docs and series, and of course innovative comedy, 'The Office' being the latest in a long line from them, Monty Python' and later 'Faulty Towers' having established them as a breeding/testing ground for new ideas in this area
Think of the major successful comedies from UK TV
since the 60's, that have done well at home and abroad, they are almost all BBC, I know for some odd reason ITV's Benny Hill was successful in the US, that is an exception though, hardly an advert for them either, it was so poor and out of step with the audience that even ITV axed it in the late 1980s.
One of the best dramas I've seen in recent years, 'Conspiracy', the reconstruction of the notorious Wansee conference of top Nazis to plan the 'final solution', was a joint BBC-HBO production, it could not go wrong with two great TV
channels involved, (HBO is by far the best US channel, but of course it's cable, free from the restrictions of the major networks, the BBC have not come up with anything as good as 'The Sopranos' and Six Feet Under' recently).
Many writers and film directors got their break and gained experience on BBC drama productions.