A non-human captain would serve no story telling purpose. Again, that whole thing about putting actors in costumes and giving them bumpy heads, and then having them act 100% human, being a waist of costume.
of costume? Sure, if you don't make being an alien part of the character. An integral part of Spock's character was that he was half human and half Vulcan. Are you truly going to contest that this basically defined him, and that (starting in TOS) it propelled the plot forward several times?
Good characterisation is working the person's species, ethnicity, personal experience etc etc into the story...you know, to have him/her react in a unique way in any given situations, interact with others convincingly etc.
Great potential, being wasted by your dismissal of this concept.
And no, not all white Christian males act alike, but mixing things up a bit would make everything so much more interesting! Sometimes, a different way to view the world and life and people is all it takes to break the routine.
Needless to say, I'm all for it.
Oh, and please less puerile romance and more diversity concerning sexual orientation and gender identity.
That's one thing that ST has been lacking: true diversity. Basically everyone is a white, straight American. Kick up the dust a little and make people real, three-dimensional and interesting. They need to write characters we can emotionally relate to.