Know what hurts my immersionz? Looking like a patchwork hobo clown.
Not really. The only options you have is AF, darklight and a fixed set of armor that your class can wear. Three choices is not "a lot", not to mention only darklight/melded armor is what is considered "not gimp" anyway. So everyone ends up wearing highest level armor melded with some materia or darklight if they are lucky - there is no visual variety and all the "pretty, creative designs" they have for other equipment stays unused because you just PL through low levels.
As long as it applies the same class/job restrictions, I don't see the harm. The system applies graphics to your character, it wouldn't be a separate appearance mode where if nothing is equipped you'll just look naked even if you're wearing gear on your normal slots.
People are already standing around in their reindeer outfits... If that's seriously a real problem, they could just restrict that stuff to normal slots only (likely, if they've stated they want us to be able to be easily distinguishable as classes).
and if someone else's preference for the way their job's AF looks really offends you, throw in the on/off switch for everyone for all I care. I don't personally care how other people choose to dress.
I guess we're ignoring militia gear, GC gear, class gear, and the variety of high level gear for every class. Don't like cobalt stuff? Roll with a Templar set, and just meld the difference. Sure, you won't be min/max'd, but there's nothing in this game that requires you to be, so dress however you want