I feel that quiet is not just sexist towards women due to her depiction but sexist towards men too. As we can all agree that quets attire exists primarily to pander to men I find the view that "men will buy this because men like tits and nearly naked girls" pretty gross . It makes the assumption that all men are controlled by their libido and are incapable of enjoying something for its own merits without shoehorning in extreme fanservice (the B&B unit counts as this too, I just was at an age where I didn't really understand the complications of this kind of pandering).
Quite frankly I find it insulting and it's one of the main reasons I rally behind feminist discussion of media in this way, because it's currently the only movement working to dismantle tropes that are applied to men, tropes that are often "enforced" in negative ways through societal pressures, (MRA is a joke that actually attempts to enforce these tropes :/ ) .
That's not to say that you can't enjoy T&A. It's just that in the context of metal gear it wasn't this "extreme" until MGS4. In all the previous games it was either in a context that worked really well (MGS3 Eva) or it was just being ever so slightly coy( Meryl) without ruining the character. Yes metal gear has a history of not being serious. But Quiet isn't isn't the kind of "not serious" the mgs franchise is known for :/ Its known for amusing gameplay interactions but the story is always played seriously (even though it is hammy at times).