It’s a lot more interesting to have a goblin that somehow managed overcome its evil nature if basically all other goblins are genuinely crooked and evil, than if they’re all “just another race” that’s misunderstood. Yes, most villains should probably be more interesting and nuanced than just being evil due to their race, but evil races/monsters aren’t a bad thing in a fantasy.
It’s a lot more interesting to have a goblin that somehow managed overcome its evil nature if basically all other goblins are genuinely crooked and evil, than if they’re all “just another race” that’s misunderstood. Yes, most villains should probably be more interesting and nuanced than just being evil due to their race, but evil races/monsters aren’t a bad thing in a fantasy.