I think we're jumping the gun a little bit and making assumptions about content that doesn't exist yet. The current system can only "make bad players" if the end-game content is handled in a radically different way, and without warning. It would be a more valid argument if FFXIV had more possible strategies that people simply ignored, but instead the only thing you really can do is zerg, barring Battle Regimens (which rarely work anyway). Unless end-game battles involve sudden micromanagement I don't think there's anything to really worry about (and even if it does people will adjust to it eventually or just be weeded out of the end-game rotation which is no different from any other game).
And I wouldn't try to add FFXIV's lack of movement during fights as a "mechanic" to base the argument on. Regardless of what kind of mechanics you're dealing with there are always going to be people who lack the rudimentary hand-eye-coordination or even attention span to avoid even the most obvious dangers (I'm looking at you, WoW, with your big giant glowing don't-stand-on-me circles that people still die to).