If Zionism is legitimite in the eyes of Yiddishkeit why were so many Rabbis against the creation of a jewish state?

That's a very good question, you should ask them that. I think it has to do with how we define Zionism, if Zionism is about forsaking Hashem and the Torah – I am against it too, if Zionism is about the renewal of the Jewish settlement in the Jewish land, reestablishing a Jewish sovereignty in the land of our forefathers and kings – so you will find it very difficult to find a rabbi apposing that.