I'm not sure I buy the argument that some people make (that this kind of material is training a new generation of child predators), but the hyper-sexualization of young women IS a problem in our society, and this doesn't help, whether it's a drawing or not.
That said... this manga is mostly doing it ironically. It's a parody of the magical girls genre, which has always had this issue. If you told the animators of Sailor Moon that people were jerking off to the transformation sequences, they'd pretend to act shocked probably, but they know what they're doing.
I particularly enjoy things that adeptly parody issues in popular genres, which is probably why I like things like this, Madoka Magica, and Kill La Kill far more than any of the original Magical Girl series.