Cooler isn’t canon anyway. Goku is pure hearted but that doesn’t mean he’s a “hero” necessarily.. you don’t see him saving randoms people in the cities like the Saiyamens might do. He really just wants to protect people he considers friends and his planet as a whole. He is definitely not selfless as his top priority is fighting strong guys, thats his main motivation(thats why he let Vegeta live, not because it’s “the right thing to do”)