2 powerful reasons: Fear and Love
1. They fear the power that White folks have over them and see them as "almost" invincible.
Often times the only time a Black person will challenge White power is when they are so desparate and have nothing else to lose and don't even give a fuck if they live or die....THEN they'll go all out and use everything within their means to challenge White authority.
....and usually will WIN.
Look at Haiti and Somalia as examples.
Problem is, it happens so few and far in between that not enough wins have been racked up to overturn the White Racist System.
Even worse, after wining and driving them out of the nation the NEXT generation of niccas will get lazy and invite the White folks back in for some trinkets and jobs.
2. You gotta be honest, a HUGE percentage of Black folks (especially in Africa) love White folks too much to fight them.
They see them as angels.
Think Florida Evans and White Jesus.....
"Boy you hush yo mouth!
Don't you talk like that infront of Jesus!!!"
They see them as being "better" morally, looking better, certainly nicer, more refined, and more educated.
They seek them for education and better standards of living.....so their own logic wouldn't allow them to destroy that which they love and seek benefits from.
How can you and why would you fight him whom you believe to be "Jesus"????