An African American saying "slavery was a choice" is just a weird non sequitur, really. It's a fucked up thing to say, but it doesn't really even connect up with the cultural memes associated with white supremacist ideologies.

Suggesting that Jews control everything, and that one is about to inflict ultra-violence on them, has been the prelude to various anti-semitic ethnic cleansing initiatives for centuries.

Of course a German company founded by two guys who both joined the Nazi party and cooperated with the war effort was going to drop him. The only real question is why it took them so long.