It's much of a muchness; a two way street, if you will, or a more or less self-perpetuating circle between individuals that make up a society and a society that is the upbringing and social pressure upon the individuals within it.
It doesn't change the fact that a goblin that stops being evil doesn't suddenly also stop being a goblin or undergo a transformation into something else because they shed their evil; That doesn't happen. It DOES happen in all-and-only creatures that are inherently and intrinsically evil in their very essence. It does not happen to goblins. Therefore, goblins do not fall into that category. Q.E.D.
I'm not saying that the majority of goblins aren't evil - they absolutely are! I'm not saying that the majority of goblin societies aren't evil - they absolutely are!
I'm just saying don't conflate their simple mortal evil tendencies that are tied up in part with their circumstance and culture, with actual inherent evil, such as is found in fiends. They are two completely different things, and should not be confused.
To GM4Him.... about zombies... have you ever watched Warm Bodies? Good film!