Well, I'm of the opinion they have the potential to grow and go on to bigger things/goals if they remain as the current 5-nin. J=J looks like a group that could evolve and forge a legacy (their own path) through a shared history much like C-ute and Berryz once were. Adding a new member that did not go thru the same shared experience these 5-nin had together kinda disturb the dynamic. These 5-nin went through the same hard times, the gruelling 225 concert schedules before realizing a shared dream. Its going to be very difficult for any new girl, however good she is, to measure up to the senior members, especially in terms of experience.