That's a false assumption from the outset. Sexualization does not actually relate to any particular perspective or quality of character development or design - at least not in any meaningful general case scenario. There are, after all, huge variations in what would be sexually appealing to any particular audience member or artist. Further, entirely repressing any expression of sexuality tends to play just as implausibly as overt sexualization. We are, in general at least, sexual creatures and huge portions of our lives do, as a general rule, revolve around exploring and expressing our sexuality.Darth Rosenberg said:When a character is designed - visually, and through writing and performance - to buck industry conventions of white, heteronormative masculinist tropes, I think it's safe to say she's not sexualised in the slightest.
Sexualization of a character can easily be an important building block of a character but like any aspect of personality or design, if that one block becomes the entire design conceit, chances are very good that your character will be seen as poorly constructed. There is, after all, something between asexual creature and roving sexual innuendo.