It's all about who's going to bring the most money into the 'box office'.
If that's a 'white' actress in the role of a Japanese person, so be it.
This has happened forever & a day in movies & theatre.
Remember our own exceptionally talented Sir Robert Helpmann who played the part of the Chinese, Prince Tuan, in movie '55 Days at Peking'?
He even choreographed (as he would do!) the dance scene in the Temple, with Charlton Heston(Maj Matt Lewis) & Ava Gardner(The Baroness). And that was 1962.
So the situation is NEVER going to change because of the almighty $$$$$$!
People should be used to this by now! All the PC'ing in the world's not going to fix it!
Actually I think a fair bit of progress has been made already. I don't think Hollywood could slip through an out an out racist caricature like the Micky Rooney character in Breakfast at Tiffany's now and not have people up in arms and boycotting the film. I think it will change, but people need to speak up about it.