Early in The Calling Gus compares his "tied-down" parental life to the free single life of other birds in the colony, temporarily longing for liberation.
Every parent (that I know, at least) experiences this frustration at some point. However, these parents are biologically programmed to give as much as they possibly can to their kids as frequently as they can. He is a piece of you. Your face is in his face. If you want to yell at him, it's like yelling at yourself. This makes the enormous sacrifice of being a parent bearable. This is what keeps Gus, I'm sure, from flying away from Riley.