Yep, the memorial is controversial -- black man in white granite, American hero carved by a Chinese artist in Chinese granite. Controversy seems appropriate, given that controversy followed Dr King throughout his life.
Perhaps this new fusion statue in the Mall symbolizes the way that history will see his significance. For us he led the second emancipation of African-Americans but globally his impact will be seen as the start of an era emphasizing civil rights for all people. He was definitely the quintessential African-American leader but his vision was bigger than civil rights for African-Americans. Yes, he was an American hero (and should be recognized as such) but his long-term impact is perhaps going to be understood as more global than American.
We should accept the statue for what it is.