Hope is actually one of the better "emo" characters from Final Fantasy, it's just that people can't stand realistic characters. Seriously, his mom died and he's trying to exact revenge on the person who he has to travel with, who despite being responsible for his mother's death still acts like a child and calls himself a hero. I don't know about you, but I'd be fucking pissed if that happened. I'm not Cooke and Mack, I can't bounce back in a few minutes after a crappy torch lighting minigame considering my mom died.
Honestly, all of the characters are pretty lame at the beginning, but the point of Final Fantasy XIII is character development over anything. Every single character has a significant change in their personality throughout the story.
The story just falls flat on its face at the end, you'll be very disappointed and confused. It's an interesting enough concept and the mythos is quite interesting, but the ending is so nonsensical that even the game script can't follow what's happening.
And honestly, it's an RPG in the slightest sense, if at all. Just because it's a Final Fantasy game doesn't mean it's an RPG. It's like if PopCap made a gritty FPS and everyone called it casual just because PopCap made it.