do you ever just sit around and think about how gross it is that a bunch of Americans took a show made for British people, that taught them great lessons, that the universe was a wonderful place, the importance of compassion in everything you do, and made it all about them, their sexual fantasies, and their political theories?

do you ever just sit around and think about how gross it is that a bunch of Americans took a show made for British people, that taught them great lessons, that accurately portrayed the effect autism has on personal relationships and a career, the importance of understanding those people, and made it all about them, their sexual fantasies, and their political theories?

do you ever just sit around and think about how gross it is that a bunch of Americans took a show made for Japanese people, that taught them great lessons, that personified the countries in WWII, that made it easier to understand political relationships between countries, and made it all about them, their sexual fantasies, and their political theories?

Welcome to fandoms, idiot.
The BBC is a huge media corporation and their TV shows are marketed towards the international market as well. The BBC has channels all over the world, in pretty much every country I have been to there has been a BBC channel of some variety. Your point is moot because Doctor Who and Sherlock are not exclusively made for British audiences.
Secondly, the themes explored in those shows are pretty universal and not exclusive to their country of origin.
As for Hetalia, if anyone thinks it teaches them “great lessons” about international relations they need to sit the heck down.