What exactly do we even mean by whitewashing?
It seems that many are in the camp of if there's a white lead in a movie which is adapted from a work of art from maybe Asia then it's morally wrong. I think this is a very simplistic generalization of the situation, take Ghost in The Shell for instance, the studio is spending so much money on making the film and would naturally want to make a profit, for that they need to be able to draw viewers to the cinemas.
Some problems arise there. First, most people outside of the general anime/manga community have no idea what Ghost in The Shell is, you are also not selling this movie to Japanese but to Americans so you need actors that would be able to bring in the viewers, I don't know if there's any Asian actress like this currently, maybe Lucy Liu but she seems kind of aged for that role.
Second, you're not making the Japanese movie version but rather adapting the original material to American audiences, people tend to forget that Ghost in The Shell wasn't even generally liked initially because of the type of storytelling it adopted where most have to watch over and over to really get a grasp on the story as it's very thick, not until the community grew older did we become able to appreciate the themes of identity etc. that the story told. Blockbusters have to be generally simplistic to be blockbusters, this means changing elements of the story to accommodate American audiences.
Could go on and on but the point is that I don't think these decisions are made by seemingly evil white men trying to eradicate other cultures as is implied, a large number of these are rational business decisions that you might disagree with of course, no problem with that, but they're still based on some type of reasoning of how they think they should go about their business.
Also you can't solely attribute the failing of these movies to be because of having white leads, there could be and most likely there are other factors to consider for the failure of these movies. Again simplistic generalization of a situation.