It's not rocket science. The money to do it the way things are done in the US doesn't exist. As the Head of Drama at the BBC pointed out recently when asked why don't make something like 'Game Of Thrones'; if they did it would eat up most of their budget for the year.
One season of Game Of Thrones could take up five or more seasons of the money used to produce Doctor Who.
Wow. I would have guessed the reverse. I don't watch it but I assumed that GoT didn't cost very much per episode. I didn't figure that filming unlikable characters talking for 50 minutes an episode, with some nudity and random violence stuck in, was so expensive. After a brief google search it seems like its mostly costumes and location shooting that make it so expensive, which makes some sense at least.
Still, when I said the differences were weird, I knew about the money thing. I'm just saying that the US could probably produce the show a lot faster than 9 months for 13 episodes, and it probably wouldn't cost that much more. Its the extreme slowness of producing episodes in the UK I find weird, and it doesn't seem like a lower budget would necessarily make it take longer to produce episodes. I mean, obviously there is a reason that the UK TV show makers are glacially slow compared to the US, and that 's the weird thing for me.