I wasn't insulting anyone who doesn't speak English as a first language either!
But the writers and producers are certainly first-language speakers.
And it doesn't make sense to invent names with spelling that would suggest an "un-English", i.e. more unfamiliar-sounding pronunciation - which would sort of be the point in the case of "aliens" - and then have the actors say them as though they were American English. That all I was saying!