As you've pointed out, you're hardly the average film-viewer. Just because you and I are "always open to dialogue-heavy indie goodness" doesn't mean that the rest of the world is. And I thought that Juno's opening scene succeeded far more adeptly at drawing its audience into that world than, say, Garden State. The Garden State opening is beautiful, but I would argue its also jarring and a little uneven (especially if you don't know what you're getting into, and people often don't.)