Well, in my eyes, Zionism is a very righteous cause. In fact, I believe that any decent person should be a Zionist sympathizer. Then again, from my experience "Zionism" is frequently used as a curse word to describe all kind of crazy things that have nothing to do with Zionism in reality. I guess you and me have a very different idea about what Zionism is.
Having or giving the Jews a homeland is a rigtheous cause. But that concpet of Zionism died when Israel was created. Pretty words mean very little when they aren't backed up by concrete actions. There is a huge discrepency in what Zionists say and their actions.
For one the concept of Greater Israel. Second the settlements. The third take the homes of existing Palestinians and converting them to Israeli settlements. These are all proponents of the modern Zionist idealogy. One that is supported by AIPAC, BB and the Israeli government.
Hardly righteous endeavours.