"Destroy" is too strong of a word, it is not the fast charge per se that is not good for the battery, but rather the heat in the long run.
In my experience, you can count on about two years at the most before ANY phone reacheargeable battery has lost capacity to the point were it becomes almost useless, even if you "baby" the phone. It is just the way it is with Li-Ion batteries, they start to age as they leave the factory.
Unless the early adopters of the Turbo and consistent users of the turbo charger have started to report already battery capacity deterioration in droves, I see no reason for alarm.
We can all have our opinion and preferences, but when it comes to engineering, usually numbers do not lie.