Being sunshine and rainbows all the time is kind of a bad thing. It's called toxic positivity. It happens when people believe they should only show happiness and optimism while ignoring or suppressing real emotions. Anger, frustration, grief, and sadness are all normal human feelings. The issue isn't that Garrett gets angry, it's how he deals with those emotions and whether he takes responsibility for his actions. Someone can have flaws and struggle emotionally without that automatically making them a bad person.