Out of curiosity, are the people who don't want overly sexualized characters in the game also against having the option of making the PC overly sexualized? Or just NPCs?
I can only speak for myself. But I'm fine (not happy, but fine) with sexualized outfits outside of fighting, but only if it fits the character personality (I find Ashley style in ME3 not really ok with her previous style, that fitted her much better, but I found Jack's style very much hers, even as ridicolous as it was. She wear her tatooes, she is at the same time naked and covered by them. For her, are more treatening than agressive clothes. From it to be real, or even give the impression of it, owever...).
Having Jack, Thane, Samara or Miranda without any sort of protection for their exposed skin in a toxic enviromant or out in space with just a mask instead of an helmet, is ridicolous. And if Shepard must wear armour, why the others don't wear it? Why are the rules bending for them?
I personally don't like oversexualized outfits, so I wouldn't want my character forced to wear those (I hated with a passion the cocktail dress), but I'm not against the chance, as long as I can have my more comfortable clothes too. One shouldn't exclude the other.
So, as long as it made sense (out of duty, on the ship or dancing at the pub) companions can wear what they want. Just as in RL, I can carre less what the other people wear. Is their body, their skin, and as long as they are comfortable, I don't care. And as long as it fits their character. (Miranda's catsuit fit her vain character, for example. Samara's anti-gravity boob window and hight heels, not so much)
I simply don't like oversexualization when is out of context, basically, and when is forced over my own character.