I don't believe it's more about socializing during combat, which is certainly a plus given higher levels, having an auto attack leaves more room for coordination such as:
Managing Buffs/Debuffs/Cures
Party Enmity
Managing crowd control

Granted this will, without doubt, add to the annoying "halfass" or "semi-afk" melees from FFXI, it was integral part of the more complex, higher level fights. The best complement to Auto-Attack would be adding the previous FFXI Skillchain/Magic Burst system in place of the current Battle Regimen system. This would allow for greater battle complexity and class uniqueness at the same time both of which seem to be common gripes about FFXIV's current state.