This was mentioned on a another thread; that we can explore all these human problems in Star Trek with human characters of other cultures and groups now, as opposed to aliens.
Now aside from the obvious, "This is sci-fi in a future where aliens exist", why do we need aliens if we can probably get the same messages across (successfully, in other non-sci fi genres) using only human cultures and situations?
Now aside from the obvious, "This is sci-fi in a future where aliens exist", why do we need aliens if we can probably get the same messages across (successfully, in other non-sci fi genres) using only human cultures and situations?