Like Saintv1 said, I think it's just a way to express an extreme for something without using excessive wording. Instead of saying "I really, really disliked it," it's easier just to say "I hated it."
Similar to instead of saying for instance "I really, really liked BvS." Easier just to say "I loved BvS."
Exactly. So in other words I strongly disliked Suicide Squad. I personally enjoyed BVS more than WW but I see why people prefer WW. I cannot see how people like Suicide Squad better than BVS.