Let's just assume King is right with this silly conspiracy theory that Taylor Swift is a dumb bimbo who can't write a song to save her life and instead steals words from other people and takes credit for it.
Led Zeppelin basically stole their songs from their influences, and yet they are still among the greatest bands in history. The Beatles got big by stealing old rhythm and blues songs from others. Same for the Stones.
Elvis stole his music, Bob Dylan did some of that too, MLK plagiarized his college thesis or w/e.