Why do people block my questions especially the ones were you know and i know i'm right?

when ppl block my questions because they contradict them and tell the true, they block it. why don't you wanna accept african history like Songhai, Mali, Egypt, Ghana, and and all history of africa and what we did for the world and if you don't believe me look at the site Ending Stereotypes for America. Why do ppl wanna be so ignorant???