According to Hugh Laurie it is...
From Digital Spy
Hugh Laurie has claimed that his American accent is the reason for House's failure in the UK.
The medical show, currently in its fifth season, has proved a hit in the US but failed to replicate its success in Laurie's native country.
The actor suggested that British audience's familiarity with him means that they are on the lookout for slip-ups with his accent.
"I'm quite dubious anytime I hear any of my countrymen playing American," he told Playboy. "I think that's why House doesn't do so well in England... The British are wise to me.
"Any sort of linguistic affectation drives the English absolutely mad... We're all out to detect falsehood and artifice in the way English speakers speak."
I thought it did quite well on Five, it seems it's usually in high in their top 10 shows of the week, and gets 2-3m viewers regularly. Seems a bit odd that it would be considered a flop.