TOS episodes were conceived as, if not written as, a metaphor for the human condition. Regardless of storylines and characters, to change that now would be to abandon entirely GR's vision.
Gene Roddenberry was also known to have said "If we aren't making a story about humans, what's the point?". Talk about writing other races of the Star Trek franchise into a corner. How can an attitude like putting us over anyone who isn't human be considered a forward thinker, or a man with a positive vision?
And it's not like Gene's grand vision was the hallmark of many great episodes. His control over TNG was very much absolute, and under his watchful eye he made the most ludicrous demands of every writer on the show. As a result, we have Picard calling a military uniform a 'costume', preaching about how we've grown out of our 'infancy' because we no longer wish to have possessions, and how humanity and humanity alone will some day be like angels and gods that may one day surpass the Q!
And if you think Gene practiced what he preached, look up the credits to the Star Trek original theme music and you may note that while he was not a composer, his name is there with Alexander Courage. What part of the theme has Gene's contributions in it? Nothing. Because he ripped off Alexander Courage by adding lyrics to the theme which he never intended to use, and as a result took half the royalties from the real artist who was just trying to make an honest living. This man not only wanted his share of Star Trek, but other people's share.
Gene Roddenberry: In the future, there will be no hunger and there will be no greed.
I sure don't mind if a good deal of STID is Earth based. One Earth-focused movie in a 46 year-old space franchise isn't going to hurt at all.
Except Damon specifically states that he wants Earth to play a more pivotal part in 'their' movies, meaning it's going to be the focus of a lot of plots should they decide to continue Star Trek their way.
