As an Asian man myself, my take on Iron Fist being white:
I have never been outraged by most cultural appropriation. If we are to live in a multicultural society, then culture must be allowed to mix, flow and be adopted freely. I want other races going nuts about Chinese kung-fu. It's a genuinely awesome cultural product, as is our food and money transfers to the next generation through red packets wishing them success and happiness. Us Asians wear Caucasian shirts and suits, we shake hands like Caucasians and we commercialize Christmas just as well as Caucasians do. As long as you're not living culture just to mock it, people already practicing the culture should be (imo) flattered and take pride in the fact their culture is considered awesome enough to be adopted.
So as a concept, I am totally fine with Danny Rand being a white guy who's immersed in Asian culture. I actually really enjoyed Tilda Swinton as the Ancient One, because she filled a directorial vision for the role and played it marvelously. My disappointment was reserved for Wong, who was done with none of the poise, easy class and snark I expected of the character.
So no complaints if Spider-Man becomes Asian next. He's already been black-hispanic.