Well I said in your type 0 thread that I loved World of final fantasy =p.
It isn't that challenging you just have to learn the game and at the beginning and I guess everyone don't like to change their 'monsters' at the beginning.
I platinumed that game aswell, it can be very hard at the end of the game to platinum it but god it is so much fun, and really sad their is no console sequel.
I think a big part of the challenge is not always being prepared to fight the boss (regular enemies too). I have this curse where I will have always have a stack that does not perform well against the boss. Your right, sometimes it a nuisance to switch in other monsters when you are specifically training certain monsters for whatever reason. I can be stubborn. I also play on active, you may beat the A.I. In the turn gauge but they will always choose their actions before you unless you know your just going to use Attack then mashing X will but you before them in order que.