He hates the Brits because they had to colonize his ancestral homeland to end the slave trade.
ObaMao probably fantasizes that his daddy and grandfather and maybe another generation or two back could have been rich slave traders and tribal chieftains who got their first pick of the women before selling their captors to the Muslim world.
And don’t forget the sex with the little boys and the voodoo dances.
The British had their part in the slave trade. But they did a whole lot more to end slavery and sustained it to a much lesser degree than did the Arab world.