I just can't believe people are defending this "strategy" and that the devs have designed the fight with such faulty mechanics.

It would be the same if you could just hold Twintania in phase 1 until rage timer, simply tossing a regen on tank and a couple of cures after every DS, then when the timer hits 0 you'd simply kill her while healing through AoEs... That would not be a strategy either, that would be using bad battle design to skip the actual battle while still getting the rewards.