Kanan was actually a decent father

He wanted Shawn to stay with his nba career goals. But when that didn't work out the Shawn insisted on being a part of the game. At that point he was a soldier first and not a son. Then Shawns dumbass started messing with Tasha, awared Ghost that Kanan wanted to kill him, then snaked Kanan. The only person to blame for Shawns death is himself.