Birds impress us for many reasons. First of all, many of the similarities between bird and human are disguised by their anatomy. Humans recognize things very superficially. As much as birds have arms, hands, and even fingers - to this day birds have 3 fingers, where 2 are fused - most humans won't even see arms. A layman will "correct" you, "nono, birds lack arms. Instead they have wings"
People are very superficial, and on the superfice birds seem very alien to us.
Birds that are badass, just emphasize this.