If the way Nina looked wasn't important than why change Zoe's looks?

I keep hearing from people who don't mind what they did with Zoe Saldana in this film trying to make her look more like Nina, which was a huge failure, and how they either don't think it's a big deal or they say that hiring an actress who looks exactly like a real-life figure isn't important but, if it wasn't important or a big deal then, why give her black-face? And that is definitely what this is by the way and it's shameful.

You can't say that it's not important to find a an actress that looks like Nina Simone or at least one that is actually *beep* black if the film-makers were going through the trouble to darken Zoe's skin and add prosthetics to her face. The way Nina looked is either an important part of telling her story or it isn't. You can't have it both ways. If her looks are so important that they would go out of their way to make Zoe look like her then, it was important enough to find an actress who looked like her in the first place, or one that was actually the same race/skin tone as she was.

There have been many other times that actors/actresses had to go through makeup changes to look like a real person, two stand-outs would be Nicole Kidman in "The Hours", and Steve Carell in "Foxcatcher" but, with this movie, it really stands out simply because of the whole black-face thing. It's one thing to make an actor who's not hispanic look more so by tanning them or something but, it's another thing entirely to try and darken an actress' skin when we have all of the issues of race and "white-washing" plaguing our society. This was just dumb and the fact that Nina Simone spent her whole life being told and feeling like she wasn't beautiful because of her skin-color, and nose and having the filmmakers do this is just laughable and also kinda of despicable.