Why so much Jewish infighting?

I think we as Jews need to stick together. Religious or irreligious, Chassid or Litvak, Ashkenazi or Sephardi... It shouldn't matter.

So then, why do the Satmar hate Jews that love Israel?
Why did yeshiva students plant a pipe bomb in the new Rosh HaYeshiva of Ponevich's home?

I think this could be an interesting debate. I'm sure Reb Elyashiv and Reb Ovadia learn the same Torah as Reb Yoel and Reb Zalman (the true Satmerer Rebbe). In fact, Reb Yoel was saved from the nazis by Zionists that bribed the border guards allowing the train into Switzerland (I know, the zionists didn't pay enough.... maybe that's why he hated them??). I won't censure the blog. I just want to understand both sides.