Maybe the guys had a great pitch for the type of movie....maybe it didnt end up feeling or looking like how they described. Kathleen Kennedy did mention that the 3 of them discussed it being a "Heist Spaghetti Western" with certain colour pallets being discussed, I think that sentence really shows that whatever Lord and Miller did, even if dope, wasn't what they discussed.

You can't say well why didn't she just hire someone who would what she wanted but they clearly discussed this. I'm pretty sure Lord and Miller are quoted saying the same thing before they started shooting. Their vision clearly just didnt line up with the rest of the lore. Do I know that for sure? No, but those sentences being brought up again show that it just wasnt right.