Except he sucks at his job too.
It's AA's job to put together a talented roster, and he's undeniably failed at that.
It's Gibbons' job to put his players in the best position to succeed, motivate the team, and reduce the amount of sloppy and flat-out bad play as much as possible - and he has unquestionably failed at that.
Even worse - this is his second chance with the same franchise that fired him unceremoniously the first time. Thinking he was going to do any better this time around after getting ZERO other manager jobs since his firing was just pure folly on AA's part. It was a classic ego move, just like all his other franchise-destroying gambles last winter. He was thinking he'd look like a genius for making it work with Gibbons of all people, and predictably, it blew up in his face.
They both need to go. Period.