"How dare a straight male depict a female as sexually appealing!"
This is one of those things that you would file under "doing feminism wrong". Unfortunately, there are a lot of people doing feminism wrong, and it's having a very powerful negative impact on the image of feminism as a whole, which undermines the feminist goals of seeking equality and reducing sexual discrimination, by instead fostering derision and opposition between the sexes, by telling women that it's in men's basic and subconscious nature to oppress women, and thereby giving men the impression that feminists hate them, and that the success of feminism depends on the subjugation of men, rather than true equality.
It occurred to me recently, while pondering the preponderance of sexualized depictions of females in the creative arts - books, film, video games - that the mere fact of female characters being depicted solely for their sexual characteristics may not, as is often assumed, be a necessary indication of the belief (usually in the creator) that sex appeal is the only quality of value a woman has going for her. While it's true that the male voice may be overrepresented in society, and that this is a feminist issue worth addressing, it's still only a matter of balance. Considering the [straight] male creator in his own domain, I would like to propose the hypothesis that the creation of sexualized female characters is not at all in conflict with a belief in the essential equality of the sexes.
Imagine the creator who believes that men and women are equal. Ideally, he would include something of a balance between the sexes in the characters of his fictional works. To do otherwise may represent something of a failure of equal opportunity, but does not necessarily indicate a discriminatory mindset. Now, if this creator happens to be a heterosexual male (which, I think, most feminists would agree is the most common case), then one of the primary differences between the sexes - otherwise being equal - he would see is the far greater sexual appeal of the female. Thus, believing both sexes to be equal, the only place where it would matter for the character's sex to be female is where she possesses considerable sex appeal. It's the only thing that sets her apart as a female from the males. The fact that all the other characters are male could simply be a symptom (albeit not a very notable demonstration) of the creator's belief that men and women are equally capable of any task, except that women are far superior where sex appeal is concerned.
Don't get me wrong, this approach is not unproblematic. I agree, as most feminists argue, that there should be a greater balance of male and female characters, and that there should exist admirable female characters who do not possess obvious sex appeal, or whose sex appeal is not the sum total of their worth. (On the flip side, which is not so often discussed, I believe there should be more depictions of "sexualized" and "objectified" men, whose emphasis is on their sex appeal - because sexuality itself is not a symptom of discrimination, only the lack of a proper balance is). But at the same time, I think we should temper the faux-feminist impulse to decry every sexy female character (whether or not she was designed by a man) as evidence of a sexist, patriarchal, objectifying cultural mindset.
There is nothing feminist about that. It is purely sex-negative, and, as I have said, it fosters derision and opposition between the sexes, which can only hurt feminism's true cause. Nothing productive is accomplished by shaming men's sexual attraction to women: it irresponsibly fails to provide women with a proper understanding of the way that men are going to view them (no amount of faux-feminist brainwashing is going to stop men from drooling over women's bodies), and teaches men that feminism is about castrating men - which is a goal extremely few if any men are going to be willing to aid and support.