Your opponent could have chosen not to put an open hand near your face. Given they had that choice, and chose to do otherwise, the act was either deliberate or reckless, and therefore worthy of punishment. You giving them the benefit of the doubt only makes you more vulnerable to future eye pokes which might be more damaging, say, that time Jake Shields scratched GSP's cornea and he had difficulty seeing.
The rules don't care; as far as they're concerned, an eye poke is an eye poke is an eye poke.
There are reasons why multiple commissions have now made it a foul to put your open hand in the vicinity of your opponent's face, and it's primarily to eliminate the "accidental" eye poke, because frankly, if they're sticking their open hand near your face and they poke you in the eye, that's not accidental, that's them making a calculated decision and deciding the benefit of whatever they're doing an open hand near your face outweighs the risk of them sticking a finger in your eye.
As a UFC ref, my job wouldn't be to make new rules, but to enforce them, and frankly, eye pokes are a violation of the rule, hence, the instant point deduction within the fight, since I'd have already gone over the rules with the fighters in their locker rooms and they'd know to to stick fingers in each other's eyes, because it'll be an instant point deduction. To put it another way, I'd have already given the warning in the locker room, before the fight.