People don't hate Zoro, people, me included, like Zoro but hate the incredible Wank that he's given.
Zoro is a perfect prototype for cool guy in the Shonen that One Piece is, like Rukawa, Vegeta, Sasuke, etc.
It's a great archetype, but I personally hate when people just have to shit on other character (other archetypes) in an endless childish race to say that Zoro is the coolest.
When I was 14 Zoro was my favourite, now my favourites are almost non-existant, but I was closer to the "finding yourself" of Usopp. Lol, remember when Usopp was relevant.