Iron Fist was just a continuation of a literary trope where a white guy goes to some Far East location and proves himself to be the master of whatever discipline/mystic ability that is part of that culture.
It was done in the 40s with many characters like Judomaster and Green Lama, in the 1960s with Pete Cannon - Thunderbolt and in the 70s with Iron Fist and Richard Dragon to name a few.
Netflix could've cast an Asian guy in the role of Danny Rand and saved themselves some backlash but it really can't be held against them that they cast a white guy.
However, it can be held against them that they cast the specific lame ass white guy they chose.
