There are many reasons why the hidden villages didn't openly confront the Akatsuki as a unified force before. That being said, every time that members of one of the villages encountered a member of the Akatsuki, they tried to fight that member. Both Cloud jinchuriki openly fought the members of Akatsuki, and it can be assumed that the other villages made similar efforts.
The primary reason why the hidden villages didn't unify before is that the Akatsuki really wasn't considered a threat until relatively recently. I doubt that the villages shared information with each other. Therefore, they probably only knew about their own jinchuriki being captured. If you think about it, Chiyo didn't even know that Naruto was a jinchuriki, and the Leaf and Sand are allies.
Other reasons include national borders, territories of operation, the fact that Akatsuki operated in two-man teams, and stability and autonomy of the Hidden Rain Village.