Kalle Rantaaho
Also, the book being originally created by one person during many years makes the fundamental structures fluent and solid compared to modern TV-writing which usually means a group of writers.
This has created a strong tradition which gives new writers good ground to bounce from.
This is, in many cases, why British TV is so different from American TV. There are more shows which have a single writer at the helm as opposed to most US shows which have a team of writers churning them out. And that's also why UK seasons are relatively short at between 6 and 12 episodes whereas US seasons often run as high as 24 episodes or more.
It's not necessarily better, just different. I like both styles for different reasons. Take a show like Black Books for instance, or Ricky Gervais' "Extras." Both very quirky, original shows bursting with personality and charm. But you could watch the whole of them in an evening or two since there were only about 12 episodes of each. Contrast that with something like Fraiser with probably more than 250 episodes. And it was consistently funny too, although in a much more generic way. Large team of writers.