In "The Crucible" by Arthur Miller, how is John Proctor heroic?

John Proctor is heroic because he dies for what he believes in. He refuses to confess to a crime he didn't do and then dies for it. If he would have confessed, sure he would have gone free but he would have also given into the extremely corrupt system of Salem back then. He would have given Abigail exactly what she wanted and she would have probably gotten away for it.