ATTN NEW USERS: I strongly suggest using a real, alter-ego email address from a reputable provider and using a Password Manager to securely keep tack of it. If you forget your email and password I cannot restore your account. These are good practices in general so stop being lazy.
It's mostly because either side thinks that they want to impose their will on the other. In the past they both understood that they wanted to peacefully separate, but ever since mass media started pushing the idea of the white supremacist that wants supremacy over all American land the black nationalists got scared and thought that the white separatists turned against them. And now, because of BLM in 2015, the white separatists believe that the blacks want to impose their will on them. It is a tragedy of miscommunication and lies.