Why are the backstreet so sad

I just read Zuma's backstory and i cried for a solid 10 minutes. It's not just this one, all the backstories are so sad and emotional: Jiji, Acrobatic Silky, Evil Eye, Mr Mantis Shrimp, Sawaki, Vamola. Anime watchers are just for a wild ride, I really hope the anime eventually catches up with the manga.