So, was anyone else slightly confused with why they keep changing the eidolons/aeons/summons.

I started playing from FFVIII, then went back to VII, then played every one since. Why keep changing most (but not all) of them?

Ifrit, Shiva and Bahamut seem to be the ones they will not touch, with even Alexander being left out sometimes (even though he is AWESOME!!).

I also did not like how you only got a few aeons in X, and how quickly they became useless as anything but a meatshield to save you from insta-death.

What are your thoughts?