Whenever I picture Uhura I see a Lupita Nyongo, at least Pegg tries to make a Scottish character sound Scottish and Yelchin attempts to sound Russian, Saldana's Uhura could be any female from the in universe United States. I give TOS and TNG a pass when it comes to African characters but not anymore.
That seems a bit arbitrary. Our one and only Uhura before Zoe is Nichelle Nichols, and I honestly fail to see where Lupita would be a more faithful adaptation of the character than Zoe. I don't remember Nichelle trying to sound Kenyan either...
Uhura isn't a character from a book where you have a specific description of her, and then you are comparing different movie adaptations with how the character is described in the original source text (eg. Storm). Uhura is Nichelle and now Zoe.. and there is no other original version of her before Nichelle. It seems like you are basically saying that Nichelle wasn't real Uhura either. I mean,......?!
And I'm all for casting african actors for african characters when they can, but just because an actress is from Kenya it doesn't make her more 'Uhura' than an afro-latina actress or, you know, the african american actress who originally played her and pretty much was the person who created the character and informed Zoe Saldana's casting still (in spite of them not looking for a clone). (**)
And it's trek. Uhura technically has a futuristic ethnicity that no one can have because The United States of Africa doesn't exist in our world. No actress can truly share Uhura's exact cultural background because even if they come from Kenya, it isn't the same version of the country and african continent (and earth!) the fictional character is from. Who is to say what is the most valid portrayal of a girl who comes from such place? How?
(**) Irony is that Lupita is more connected to her mexican nationality and culture because that's where she has lived the most. Just like Zoe is proud afro-latina but still identifies with her american nationality too. They both speak English and Spanish fluently.
Ps: interesting you think Zoe nailed Gamora, instead, in spite of the character being very different from the original comic version. Maybe you know other zehoberei people and the new version is more authentic to them? I don't know...