There is a long list of countries other than the US and the UK. I will go to bat for the US on this one though and say that one might want their data in the US because of the first amendment. Even for people that reside in the UK, what is the selling point of having data with them in the same country?
For all its flaws and limitations in practice, you have far greater data privacy in the UK than the US. Largely because it seems you basically have none as a private citizen in the US.
