When you allude to abuse, you're once again mixing two concepts, which are the exploitation of children by others for whatever reason, and the actual appropriateness of certain types of clothing for those children.
The more relevant argument made by the article refers to the impact of sexualization on children due to inappropriate clothing and beauty standards. However, it also gives the sources of this sexualization. It is imposed by society in the form of standards of beauty and imposed on them by choices made by adults for them about the clothing they wear.
In the absence of these forces, one would simply be assuming that a child's choice of clothing would be a symptom of sexualization.
I still get what you're saying. If we were in a perfect world, this wouldn't be an issue and anyone could wear basically whatever they wanted, or nothing at all, whatever floats their boat.
The problem I have with what I assume is essentially a correlation but not causation argument that you're making is that the devil is in the details. Women as adults are also susceptible, clearly, to this problems, and some suffer greatly for it. But, in general, they are at a far greater level of not only sexual and mental maturity, but also in their greater understanding of themselves and the world they live in and its consequences. A child, however, is exceptionally vulnerable to outside influences, their brains are not at all fully developed, and their coping mechanisms and sense of self has not even grown close to that of the average adult. These are all important things that eventually serve to distance the actual act of, say, wearing provocative clothing with the psychological issues.
In an adult woman with these issues, it would be easy to say that there is a self-esteem issue that needs to be addressed and that, yes, perhaps certain behaviors she has (trying to obtain an ideal beauty standard) is a symptom of that and not the other way around. In a child, however, that is likely not the case--the concept of not being sexy enough or pretty enough is often quite foreign until something makes them acutely aware of these issues, such as being introduced to products like clothing designed to "improve" their physical appearance.