The BBC iPlayer works well at what it is supposed to do: provide catch-up TV services to UK viewers
It is not intended to provide service to overseas viewers. There would be too many copyright problems involved if that were to be allowed
1) because much BBC content is of foreign origin and the BBC only have UK broadcast rights - not global rights
2) the content that originates in the UK is usually sold on by the BBC for broadcast in other countries. By providing their own overseas service, the BBC would be competing with their own customers - so sales would stop
3) there would be severe complications over artist's performance rights and payments