You are saying all science is "racist" because it associated with the system. First stop is define exactly what you mean by the word "racist". I've heard it used to describe people who use a race concept (which is scientifically valid) and to people who attach superiority to some races (which may also be scientifically valid).
Your trouble is that you think "racist" means untrue. It doesn't. It doesn't mean very much at all. Otherwise go ahead and define it, and demonstrate that Blumenbach was "racist".