This happens with quite a few programmes that we have imported from the US. Off the top of my head I can think of Mythbusters and Ice Road Truckers which are dubbed by a British narrator with a lot of the dramatic music removed. All in all it makes the programmes more factual.
Personally I believe this is because of the BBC and to some extent Channel 4 (a pseudo-public tv channel) keeping standards high overall. I doubt the viewing public would accept such dramatised documentaries on the BBC considering its heritage...
What's left of Ice Road Truckers if you remove the dramatic music and dialogue? It's amazing how that show can spend almost an hour building drama about how someone is going to finally fall through the ice, yet in the end some random truck's tire slips in.
Personally I believe this is because of the BBC and to some extent Channel 4 (a pseudo-public tv channel) keeping standards high overall. I doubt the viewing public would accept such dramatised documentaries on the BBC considering its heritage...