If we look back in television history the US has "Borrow" ideas from the British for decades. The list is too long to list. American television networks like to take successful British material because it's proven to have a market with audiences. They tend to Americanize the shows, using the stories and characters in an American setting in hopes that people will better identify with the stories. It sounds like they are lazy and want $$$$$ quickly instead of just doing it themselves.