I haven't played X-2 but I'm getting it soon, like 1 week soon. So I hope it is good.
In regard to the topic, I think that every Final Fantasy deserves a sequel. X-2 was created in the "Age of Experimentation" of Square.
-First FF with voiceovers (FFX)
-First online FF (FFXI)
-First multiplayer FF (FF:Crystal Chronicles)
-First direct sequel (FFX-2)
-First female-led FF (FFX-2)
-First handheld FF (FFTA)
I don't blame Square. I think its good to experiment. Bubble gum was a mistake and look how popular it is now.