The convenient truth of the matter is that you don't want to drain your battery "to 0" regardless of whether or not it increases wear and tear on the battery, because you don't want to be stranded. As such giving lifetime aspects under that assumption that people won't do that regularly is fairly reasonable.

On the flip side, I agree that the "100%" mark should be the mark that people regularly charge to, people don't leave empty space in the tank for fun.