Well I like the AA system and don't see the point of toggling it off to manually press the attack button.

That being said, as OP mention if some would prefer it that way they can add this toggling AA off and then the Attack action (would still cost 0 action point) would be shown on the action bar and you would have to press it to attack but it would have a cooldown corresponding to the AA delay (weapon delay + haste buffs and all).

Both of them would end up being the same if the manual AA person would spam click/press the attack button so they don't lose a fraction of a second to perform the attack but if that's what they find fun then good for them.