People hate Hope because he was actually a human being compared to:

"My mother died, so what?"

and

"Hey I'm the lead character, I'll be one of your tour guides for this here Final Fantasy game (FFVI)." Which I think aside Tina and Celes not many of them had any actual emotion.

Not to mention the only child character (who acted like a child) was basically shot to her early 20s through storyline (Rydia), since while there were young characters in other FFs (Quite a few of IX's lead's, i.e Zidane, Garnet, Eiko, Vivi) they acted well beyond their assumed/stated ages. (I don't count Relm or Palom/Porim because their circumstances were quite different, and even Relm was more mature about a lot of her situations, while you lost access to Palom/Porim for a bit of the game and had no development with them.)

And yes, Hope is quite different, but as said -- If you watched your mother die, as a kid, and get pointed at who was to blame you'd act the exact same unless you're the type of people who have no emotions at all, which is possible.