Kakashi i think because he is so calm and friendly but ruthless at the same time. Also him dealing with regret and mistakes of his past shows he is vulnerable. Yet he keeps his cool and does what he must. This combination makes him great. He has been shown dealing with his past since part 1 until he finally had to face it head on. And he showed he is far from perfect but can endure. He is an excellent example of those who endure. Though so is itachi. The difference is itachi killed his own clan he had to endure that pain but he did what was best for the shinobi world. Kakashi had to deal with his mistakes that led to the false death of a comrade and a promise he failed to keep to that friend. He was never strong enough as strong as he was. He than failed to guide his student. Itachi did what he truly felt was right and gathered no hate from his parents only respect for following his own path