Sure, it's a different environment compared to US television. In the US, we're much more concerned with filling out a semi-stable programming schedule, though we do make allowances for mid-season replacements for shows that get canceled before a full season is done. Mini-series focused around telling a particular story come up, but they're comparatively rare on the big networks.
In the UK, you get some shows that fill programming slots like East Enders or Coronation Street. Those are more open-ended shows with no particular end in mind like most American series. And then you get a significant number of short run series focused on a particular story or that run for as many episodes as the writers intent to write before they move on to other projects. And I think that culture of the short-run series informs other parts of the programming environment so that you have actors like Christopher Eccleston who was a brilliant Doctor Who but declined to do any more than one series of an otherwise open-ended show. They have plenty of other options that won't tie them down, there's less pressure to continue on in the same successful show and role, in part, because there is a culture of the short-run "tell the story and be done" show.
I also wouldn't be surprised if having a history significant state-funded television has helped develop this culture by establishing alternate ways for shows to be profitable (or at least not unprofitable and worth doing) other than just finding sponsors willing to hitch their product's wagon to particular shows and advertising time slots.
