I'd agree that Diamondback is the worst Netflix villain so far, but I don't think he's bad - just not good enough to be on the same level as Kilgrave and Fisk, even Cottonmouth. Luke Cage messed up villain storylines a bit. Diamondback shoulda been better written. Even though he had some great moments (n----, I am your brother!), he wasn't compelling as the others were. He was a textbook example of 70s over the top movie villains. But I don't also think he's the main villain, the big bad. For me, Shades and Mariah are much closer to that concept considering their actions and significance for the plot and characters.