Symbolism, Imagery, Allegory
Crash and Burn
Wings conjure up feelings of freedom—you know, like, soaring through the sky without a care in the whole world. The wings in Daughter of Smoke and Bone? They're more like Icarus's big flight; first, there's a big flight, then there's a big fall.
Crash and burn, baby. Emphasis on the burn.
Some of the first wings we see are Karou's fake wings, which are made from real feathers. "She understood that birds had been killed for them, whole species driven extinct" (5.21). She calls them Angel of Extinction wings, but she's not glorifying that extinction. They're more of a reminder of how her job, and Brimstone's magic, causes pain.
Akiva's wings cause pain, too. When a nun catches one of his feathers, "It burned, and left the perfect outline of a feather seared into her flesh" (7.8). Ouch. Can you at least sell those on eBay?
Anyway, these two sets of wings really come together when Karou brings Akiva home and realizes that "her Angel of Extinction wings [are] uncannily like his wings" (30.4). Later in the novel, we learn that Akiva could also be understood as an angel of extinction, seeing as how he tries to eradicate all species of chimaera from the world.
So much for wings being all soft and angelic and beautiful, huh? These wings are fire:
[Akiva's] wings unfolded; they came around like a pair of great fans so the two of them were in a room of fire, more than ever in a world all their own. (34.54)
That's not a world we're sure we want to live in. It's the world Akiva's people have created: one of fire, destruction and death. If we had wings, we'd fly away from that. And fast.