Thanks for finding the interview and posting it!
I understand it a bit better now, although her power isnt a nuclear bomb, or some dark magic, or a machine that spies on the entire world (Person of Interest tv show), it's merely a boost in speed and strength (and not even through drugs or something, it's in her nature). So while i would understand it in these situations, here it's more like WW not lifting 100 tons but 80 because those 20 extra tons will make her lose herself.