You have not earned the right to criticize one who achieved so much in his lifetime - particularly not one who, even in the context of imperialist racism that every single European nation practiced in the 19th century, could say things like, "I could never accept the position that we should disqualify a human being on account of his color".
You have not earned that right because you have not achieved anything to set against, and be measured against, his achievements. His example inspired more than one generation, and was remembered long after his death by both black and white Africans. What example have you set by which to be remembered? Flinging excrement at statues?
It doesn't matter what color your skin is, or what your background might be, or what your aspirations are. What matters is what you achieve - and don't tell me that the lack of things of which you feel 'deprived' holds you back from achieving. That's politically correct claptrap. Good men and women in every nation, of every tribe, ethnicity, language, creed and color, have achieved great things after beginning in absolute poverty with nothing and no-one to help them. They earned the right to criticize others on the basis that they proved themselves by their deeds. You have not - at least, not yet. When you have, come and talk to me again. Until then, shut up.
The Rhodes Scholarships that Cecil John Rhodes founded have educated many of the world's leaders, including US Presidents. His philanthropy is visible in the grounds on which your university stands, which he donated, and in Rhodes University in Grahamstown. You apparently see no contradiction between deriving personal benefit from his generosity, and throwing excrement at his statue. Shame on you.
You, my brother, speak the truth. God bless you.