The problem is not that the main characters have focus, it's the complete neglect of the others. They don't have any interactive content at all. Nothing, null, nada, niente. They are no more than zombies, and that reflects back on the game's general tone.
If you don't see how introducing characters at the beginning of the game and then leaving them as non-interactive husks for a large part of the story (all of it so far) is a major issue with presentation and expectation management, well, then I don't know what to tell you.