(Overwatch's character designs are the business; as much as I love the other female character designs, I'm glad that they've created a new female character who doesn't fit into the thin/leggy/"hourglassy" mold. Anyways...)
I'm not saying that anybody has to like it, but in character design readability is a key concept; first impressions mean a lot, people should be able to gather plenty of useful information from your design in almost a few seconds seconds of looking at it.
With a character like this I can't blame them for defaulting to the whole "boob sock"/boob armor thing.
For a long time there were people asking whether or not this character from Steven Universe was a boy (it was particularly more prominent in regards to
her older designs)
mainly because of her figure and hair...and the thing that gets me with this is that her body shape (unlike Zarya's, unfortunately) is generally associated with femininity.
Most of the world's prettiest androgynous male models and fishy/convincing drag queens have this body shape and they're often believed to be women by most people.
Even though I don't think large muscles or a thick body is exclusively male in any substantial way, I do realize (going by a very adamant poster in this thread) that a lot of people unfortunately still do.
Hopefully, character designers can start getting away from unnecessarily adding in boob armor/"boob socks" to characters like Zarya in the future though; better education about sexual dimorphism in humans (which believe it or not is pretty low compared to a lot of other mega fauna), the arbitrary nature of gender constructs, and the fluidity of human gender identity and expression might lead to this.