I think people tend to hate the most relatable character in a fandom the most because we’ve all had to face one.
Like Mako. I’ve had to deal with a Mako before and it’s so easy to hate a guy/girl who broke your heart. Haven’t you had a great friend you thought liked you… Only to have him/her pick another girl/guy? Haven’t you had a great boyfriend/girlfriend only to see him/her leave you for someone else?
It sucks. I’ve been there in both cases. But the worst part is knowing I’ve BEEN a Mako and what we do isn’t out of spite or douchebaggery - it’s out of humanity, inexperience, uncertainty, and fear.
So cut him a break. He’s doing his best.
adult!zuko maxed out on the sex scale