A Feature in FFXI that annoyed my friends and me, was being forced to look at hats/helms.
Granted its a feature created in other MMOs like WoW, and Aion (and others), but it had a reason.
MMOs give you the ability to customize your character, and they do it for a reason. Its what the players want.
If the decision was to be more 'realistic' I'm going to have to say yes helms are more realistic for battle harden tanks... but hats are not. They are a fashion accessory.
Players shouldn't be forced to wear Tall pointy Hats for Accuracy, Turbans with feathers for Haste, or any other type of frilly big bonnet with feathers.
They only do it because they MUST do it, to match melees who wear helms for stats.
There are ALLOT of people who care about how they look. My Girlfriend refused to play FFXI, solely because of this issue.
She loves RPGs, but when she plays a character, she wants to avoid looking like Hobo the Clown.
If it really didn't matter what players thought, when it came to character looks... then why implement a character creation menu? It's more realistic to be unable to chose; Gender, Hair color, eye color, size, skin tone, etc.
The ability to have some customization of armor/clothes is a nice touch so far, but me and my friends would all love to finally see the day where we stop wearing Emp. Pin at Lv75, or MP pins, just to avoid ugly hats.
(I actually leveled up PLD in XI JUST because I could wear the AF/Relic in place of a helm.)