I figured as much but the main thing I am getting at is who decides?
Is a neutral accent the one that you are accustomed to hearing most often? There are a lot of acceents that are easily understood but are not mainstream, why not use one of those?
On a side note:
The same can be said for all the evil fuckers in movies, their accents are always either a English or German, what gives?
Remember the film 'Alexander', they all had Irish accents! Weird wasnt it!
We are so accustomed to hearing classical greeks, romans whatever, speak with a specific English accent that anything to the contrary just doesnt fit.