^Contrary to popular belief *ahem*...the UK isn't full of just white people.

And you've missed the point. It's the stigma attached to any hip-hop outside US. Which is done in English. Esepcially the UK.

And therefore, as you said, people in the US will find it hard to find a 'link' between themselves (their lives, tastes etc) and UK rappers in general.

It isn't ten years behind. Except maybe in terms of mainstream coverage. Maybe.

On a final note. I know a fair few people from the US who listen to UK Hip-Hop. As well as US hip-hop. And people in France (probably the biggest hip-hop scene outside US) have much respect for UK hip-hop.