Banners are by their short nature cutesy, and clogged with inferred emotion.
The way to express your point without the emotions that might sink our movement is with facts.
cold, hard, emotionless facts.
Any banner except a post-Pioli-firing one is going to come off as snarky.
It's already been said. We need a creative next step. Something similar to the food drive, but even more focused on Pioli's damage to the franchise.