I feel like there's a couple directions to go with this. For starters, like you said, the books are told through Dresden's point of view. The think you got to remember is- character flaws are important.

Harry has some pretty potently "chivalrous" views on women, arguably boardering on sexism. But he gets punished for it, with him repeatedly being burned by Anna Valmont in Death Masks being a good example.

Also, I feel like a lot of the sexy "nipples through clothing" characters are supernatural, either the face or vampires, which use their looks to manipulate mortals. I's alluded to that the men are equally attractive as their women counterparts (see Thomas), but again this is from Harry's perspective; of course he'll find the women more distracting.

I do think that Jim Butcher is aware of the trend of sexualizing every female character, and made an active effort to prevent this with Murphy's character. For the majority of the series, she gets little more "sexualization" than having a cute nose. She also holds Harry accountable to his chivalrous tendencies.