He's the one that makes things up on the spot and stubbornly maintains them as canon.>Why's the moon not destroyed in later games?
You're just seeing the other side of it.>How come we didn't see humans in Colors?
There's two worlds and Sonic wasn't in the human world for that one.>How do they get between these two worlds?
They use portals that have never been seen or even referenced before.
There's other reasons, like how he wound back Sonic and Tails' character development in Colors and kept them static. I do actually agree with you though, whether Iizuka's directly responsible for every bad decision or not, the higher ups are the ones okaying these decisions so ultimately it's their fault. It certainly wouldn't be the first time Sega made a stupid management decision.