He saved people his whole life using his own power. He couldn't save some people, but he saved the ones in front of him. He never was anything more than the action of saving people, and nobody understood him. If he had been a fail of a person like the rest of them or some self-espousing paragon of humanity, they would've understood him. But Archer just wanted to save people, because he could only think about doing what he felt was the most beautiful thing in the world.
He fought for others until he was finally betrayed and killed by the people he saved, but only after he sold his existence to the World so that he could save a few people at the expense of himself. Then he became a Guardian and got called to calamities by the world so that he could... kill hundreds of people to save thousands more. For forever.
His ideal led himself to this, but he couldn't come to hate his ideal, in the end. Just himself.