More often than not "cultural appropriation" is a misused term when it comes to hip hop. It has become a catch-all complaint about white people in hip hop, and I think that's corny. Personally I don't like Macklemore's music...but I'm not going to say he's "stealing" anything. He grew up listening to rap and sounds like an aughts backpacker, all the way down to the awkward flow. Iggy Azaliea...meh. From what I understand she was a model/pop singer who turned into a rapper. That's more egregious but then again, rap is full of shit like that, plus "fake" people. Look at Tyga yall. Should he get a pass because he's black? What about Drake?
The majority of the biggest rappers in the world (ie Drake, Hov, Wayne, Kanye, Kendrick, etc) remain black. What we're seeing recently is a demand for pop rap beyond "do molly/smoke weed" anthems. The most successful young rappers all talk about a variety of shit, identify with their fanbases, and understand how to make crossover rap. All we're seeing now is a wave of white artists doing what Kendrick, Drake, and Cole have been successfully doing over the last 4-5 years. That's it. Whether any of them have the staying power of those artists remains to be seen. I'd bet money Iggy will be thrown in the bushes very soon considering her album hasn't sold well and she's horrible live.
It's funny how white money has propped up hip hop since day one, yet now people are mad labels are pushing white rappers beyond just Eminem. Go see any rapper live and tell me what the audience looks like. White women dominate record purchases. If black people want to "take things back" they can start by buying some fucking music, or going to concerts. I've seen Robert Glasper and Esperanza Spalding live and was one of the only black people there. SMH.