You do realize...99% of the complaint about animation lock was the Ifrit Fights, right? You rarely heard people complain about it in Moogle Fight (even easier than Ifrit) and Garuda Fight (it can screw you but it was already a decent challenging fight.)
Well it sticks out like a sore thumb there because mobility is so important (and players coming from FFXI are not used to the kinds of attacks that make it so important), but it's hardly the only time animation lock is ever an issue. It's annoying in dungeons and other places as well where it doesn't ruin you but slows you down unnecessarily when you just want to get on with it after doing what you were doing.

Animation lock vs GCD:
Again, i'm scratching my head at why everyone pits these two things against eachother. Neither one of them is truly necessary for anything, so to me it's like asking me if I want my poison injected or ingested.