Lots of people attempt to refute, or at least deflect, criticism of hypersexualized female characters by pointing to all the equally exaggeratedly buff men. Feminists often respond by pointing out that these exaggerated male bodies are power fantasies for men, whereas the implausibly voluptuous female characters are sexual fantasies for… well, also for men.
Actually, let me address that bit briefly: A big part of the problem is the asymmetry of how the hypersexualized women aren't for the (dubious) benefit of the female audience in the same way that the hypermuscular men are for the male audience.
There's merit to the idea that both forms of objectification are primarily for men, but there's also merit to the idea that these exaggerated, unattainable male bodies are hurtful to the men they ostensibly benefit. This is an important issue with a lot to unpack, from the historical prevalence of misogyny over misandry, to the double-edged nature of sexism, to the various meanings of the phrase “male gaze.” I don't want to dismiss all this as unimportant, by any means, but it's also not the part I want to focus on in this post.
Rather, my focus is the rejection of the argument on the basis that the objectified female characters are a sexual fantasy while the objectified male characters are a power fantasy.
This seems like a good argument on the face of it, and I don't fully disagree. The objectified male characters are given attributes that are directly associated with power, with the ability to act on the world and the people in it. They have muscles. Muscles do things. They make things happen. Female characters, on the other hand, usually just have large breasts, or exaggeratedly curvy bodies in general. Don't get me wrong: Breasts are great. But they aren't much for enabling women to act on the world, except in fairly limited, even contrived, scenarios.
The argument isn't wrong, so much as incomplete. Here's the catch: Big muscles and a powerful build are tied to male sex appeal in ways that they aren't tied to female sex appeal.
Again, don't get me wrong: physically strong, fit women are awesome, and attractive. Physical fitness is a sign of health, after all, and health and “fitness” (in a slightly different sense of the word) are among the key ingredients of what makes people attractive. But big muscles are not signs of feminine attractiveness in the same way that they are signs of specifically masculine attractiveness.
The key here is to look at the differences between male and female secondary sex characteristics. Naturally, secondary sex characteristics distinguish one sex from the other, i.e. they're different from one sex to the other. That's what makes them sex characteristics, and not just characteristics of people in general.
Female characteristics include permanently enlarged breasts, wide hips, and an overall smoothing and rounding of the body shape. Male characteristics include broad chests and shoulders, an overall larger body, and increased muscle size and mass. In other words, that hypermuscularity is an exaggeration of a male secondary sex characteristic, just as voluptuousness is of female characteristics.
The upshot of this is that it's impossible to exaggerate the musculature of a man without also sexualizing him at least a little. Likewise, it's fairly difficult (if certainly possible) to sexualize a man without making him muscular, because muscles are such a part of the overall masculine body shape. The thing that makes men appear stronger is also the thing that makes them appear sexily masculine. (I say “appear stronger” because big muscles aren't necessarily strong muscles. Then again, big breasts don't necessarily function better than small ones, either, but they still work on some level as signifying fertility in the same way big muscles signify strength.)
So it's really not fair for anti-feminists to say that male characters who are hypersexualized via their big muscles are equivalent to female characters who are hypersexualized due to their voluptuous curves, because those muscles are tied to agency and power in ways that voluptuous figures aren't. But by the same token, because of that link between strength and male sex appeal, it's not fair for feminists to insist that such hypermuscularity necessarily isn't a case of sexual objectification.
There is one other thing I want to touch on before I wrap up: The original argument, that sexualization of female characters shouldn't matter because male characters are also sexualized, would not be sound even if its premise were true. At best, it's the wrong way to resolve a double-standard. At worst, it's just a deflection, somewhere between tu quoque and whataboutism. Either way, the argument fails because two wrongs don't make a right.
Fortunately, there's a very simple fix for all this: Avoid objectification, sexual and otherwise, altogether. Treat characters as people in a story and not as conduits for the audience's baser impulses.
But I guess that's hard and stuff.