I reckon the reason is uk banks want accounts with UK address only is because if there is a default on the account such as overdraft abuse, unable to pay, no regular payments or use of the account they have a uk address and maybe retrieve some of the money back.
In Thailand I could easily abuse my uk account so what can they do other than freeze it but to recover any losses I don't think they can do much.
I do have restrictions still which doesn't effect me I'm just glad that things keep rolling on like clockwork and can basically just use the uk banks still and not have to think about it.