I understand why youíre upset, but I donít think you can really blame the BBC.
Keep in mind everyone in the UK pays a tax or licence fee for television programming, so BBC programs are advertisement free. Since streaming broadband content still isnít that cheap, especially with no ad revenue, the BBC limits their content to the people who have paid for the programming. This helps keep cost down for the BBC and probably also improves quality of service for UK users.
So then how come the BBC doesnít create a streaming version with ads for overseas customers? Well letís say a US network wants to pick up the latest season of Doctor Who. Do you think theyíd be willing to pay as much for a show thatís available online? Probably not since they know their ad revenue wonít be as great since there's a decreased number of viewers. Broadcast regulations can also play a part. I live in Canada and canít watch most streaming shows from US providers since a Canadian broadcaster also carries the show. In this case the US providers arenít blocking me for financial reasons (theyíd like me to watch the show for the ad revenue Iíd give them) but theyíre prohibited from doing so thanks to archaic broadcast laws.
So in summary, I agree with you fully that it sucks, but I donít think itís because the BBC are trying to be idiots.