He is a hero in the eyes of the society that created the myth. As ClassicsFan says, he has all of the attributes expected of a Greek hero. The fact that his end is so tragic is an acknowledgment that the gods are pernicious and the fate of even heroes is not guaranteed to be ideal. In fact, a tragic end seems to also be a necessary quality to be a hero. Jason and Herakles are two that lost their families through their own if unintentional, actions. So, for me, it’s yes. He is a hero. Not a title I personally would want!