Specifically it is just rewriting the old fairy tales so instead of the hero being helpless they are all butt kicking warriors and wizards who defeat or convert the villain.
My personal reason to it is more... "Ehhhhhhhh"
I mean would Beauty and The Beast (Disney version) be improved if in the last act she busted out of that basement herself, rode her horse clad in armor, and beat up Gaston herself... then used a potion she made to cure the beast?
Why not... write your own fairy tales inspired by the elements of the book? Though I guess the answer to that is it isn't marketable.
Usually whenever I see one of these things rewritten to turn the female lead into a badass it tends to be terrible... Right now I am trying to think of an exception...
But I at least sympathies with parents... How much wealth of children's books are there where the female character is the hero determined by her own physical strength and combat skill and not just strength of character, intelligence, and wits (Since there are A FREEKEN metric ton of those...)... You know excluding all those that exists.
Actually on that subject I HAVE seen a book that is like a rewritten fairy tale where they turn a character awesome. It is Thumbelena except she has a sister, specifically her sister was from a weed that her mother was told not to allow to grow, but she did anyway. So she is pretty much bratty, somewhat of a trouble maker, somewhat tomboyish and raggy. Yet when push comes to shove she is the one who solves everything (mostly because thumbelena can't really do much herself) and is a good person at heart. What I actually really love about this story is that by all means our hero is pretty much the "unwanted child" whose mother decided to love anyway, and is rewarded for it. She is set up to be the disaster in the waiting that will ruin everything, but in the end she is what sets things right. It also never really says either Thumbelena or her are "bad" so to speak, and they are never put at odds with each other, so it is a book that teaches that there is more then one way to be a girl.
Add in that she does everything she does in the book, from helping her sister Thumbelena to her mother, because she is an honestly kind and caring person... and she is just the kind of character I love in a protagonist.