From what I've seen of European TV on my travels (and I always make sure I get a room with a TV!) they just don't seem to make their own comedy shows. They love their big entertainment / chat shows that would seem really old-fashioned to us, and they seem to make quiz fomats last over an hour at a time. I've only seen American sit-coms dubbed into whatever language.
I've some German friends, and once had a German lodger who just couldn't understand why we had so many comedy shows as he said they don't make them in Germany. I made the awful mistake of suggesting he watched Fawlty Towers (when they repeated it in 1998 on BBC1) only to find it was "that" episode

He took it ok - and loved the line about invading Poland! He also loved One Foot in the Grave. Across Scandinavia and Germany, an annual New Years Eve tradition is to watch a long-forgotten black and white British TV comedy sketch by a guy called Freddie Frinton (Dinner for One) - which says something about their expectations from TV perhaps? Benny Hill is still popular in parts of Europe I think.
I shared a house with a French guy once, he also couldn't understand our love of comedy shows and dramas - they seem to have films and the chat/entertainment formats in peak-time in France (which of course he claimed was far better).
There's a couple of other reasons too perhaps: in the US and UK TV is a huge part of our leisure time - I wonder if Europeans take it quite so seriously or so central to their culture? Also, Britain and the US are (I'm sure someone will correct me if I'm wrong here) the biggest original production centres so perhaps we don't need to buy in from elsewhere -and have to dub or subtitle it (which just isn't going to wash with most TV watching Brits - and even less so in the US I imagine.