That's also where I heard it. It might be a fine story, it's just sort of an odd choice for SF/F. I think the Sad Puppies campaign is a backlash against this, among other problems they see with the genre.
What just makes it that much more odd is that the Nebula is a jury award, and is arguably (with the Hugo) the pinnacle of the industry. The author is pedigreed and connected well enough that she was a quite an industry star, and that may have helped her otherwise not SF/F work - Iowa Writers Workshop, UC, etc.
I makes sense that SF/F should be diverse and progressive, it's just a little weird to see the awards spin fairly far off base from the roots of the genre.
There is also a popularity gap. The works that win are trending down into more obscurity, except in some categories. I mean this year's nominations include self-published works read by not more than a few hundred people, and episodes of Game Of Thrones, seen and loved by millions.
Seems like disarray.