Do you mean why do I hate Ezri?
Well, I think the main problem had something to do with the actress who wasn't good enough. Jadzia was my least favorite before her, but Ezri was annoying. Her constant complaining about space sickness and nervousness was supposed to feel honest, but wasn't properly conveyed. Any episode focussing upon her was lousy. I'm shocked to read some of these least favorite characters. I LOVED Zek, Fontain, Brunt ("Say hello to these POOR PEOPLE!"), and Wynn. Ziyal didn't bug me much, but I really liked her toughness conveyed by that first actress in her first 2 Season 4 episodes; I wish they hadn't changed her, but I guess they wanted someone more womanly for Garak; the second actress wasn't given much, but she did great work on a Season 3 "Millennium" episode. I guess we all liked different things, but I'm surprised more people didn't hate Ezri. I hated that Bashir's last few episodes were spent focussing on her; I kept thinking, "You can do better!"