>completely ignores Robotnik
>straps the fuck up to get back at some dude who took Knuckles' yo-yo
Why was the Brotherhood like this?

Speaking of villains, let's not forget one of Mobius' greatest monsters... Monk! Eggman? Eh, he's just a scamp, not our problem. But this guy? He stole Knuckles' yo-yo. The Brotherhood recognizes this as the dead serious threat it is, and they mobilized immediately.