Who is, at its very essence, British and should remain as so.
By the same token, us Brits should avoid trying to make stuff thats essentially American.

I think the whole idea of Hot Fuzz was basically saying that.
Pegg maybe a fan of big cop buddy movies, but he knows there is no way we could make one over here without it looking absurd.

Lets face it, if the US networks decided to do a US version of Who, it would end up like Star Trek or something!