America does seem to like British actors these days. You see them all the time on American TV series and they are quite convincing.
As long as an actor can convey the character they have been cast to play, doesn't seem to me that it should matter where they come from. We have Americans playing Brits here and as long as they act well and can do the accent, who cares? I'd have thought several people would audition for a part and the best one selected.
Still, if Samuel L Jackson is saying foreign actors are taking work from American actors ...... why does that sound familiar?