fluffybunbunkittens
Hero
It's because their history is a mess. Sometimes egyptian soul reincarnation destined lovers, sometimes alien society whose high-techness manifests in blunt hitting instruments...What is it with hawkman/girl anyway? They often seem to appear in a supporting role, but never seem to get much explanation or character development.
They're just there for aesthetics, which means they need the rest of the team around them to carry plot/character forwards, but then, in Justice League-level team-ups, being able to fly (but not super fast) and be strong (but not super duper strong) aren't really leaving a unique spot for them.