In reply to stp:
It's not unheard of, we have had World Cup events in the UK in the past, perhaps we are waiting our turn, or maybe nobody has offered a suitable venue, now that the rounds attract 1000+ spectators you can't stage it in a climbing wall, it would need an exhibition hall or something, maybe the IFSC can't afford it?
To be honest I'm just guessing but I agree it would be good to have a round in the UK again, maybe if Shauna wins the overall then some more UK interest will jump on the bandwagon?