Approaching the Bible as a design project, you confront a central tension between the needs of the page and the needs of the book. When you open your Bible, you see the page -- or to be more precise, you see a page spread, two facing sheets. As a reader, you experience the text one page spread at a time. Between them, a designer and production manager and can make certain choices to enhance that experience: a legible and reasonably-sized typeface, elegant proportions, generous margins and line spacing, even dense, opaque paper. Distractions can be minimized or eliminated. The end result is a page that doesn't call attention to itself, serving as the proverbial windowpane.
But some of these choices will impact the overall book. A generous, reader-friendly type size and balanced margins might make the page work best, but they also add bulk to the overall volume, requiring more pages to contain the words. That means the resulting Bible will be bigger, but also more expensive -- both of which make it less attractive to today's consumer, who seems to prefer things inexpensive and insubstantial. Thus the tension. Do I privilege the page over the book, or the book over the page? Do I design for the reader, or for the consumer?
In reality, you have to do both, and that's why instead of "perfect" Bibles we have a variety of compromise measures. Smaller type and thinner (nowadays cheaper) paper equal a portable format, and readers must learn to cope with the inconvenience, some managing better than others.
In an ideal world, the page spread would trump the overall book every time. But this is a fallen world, so perfectionists are always going to be dissatisfied.
I see two signs of hope on the horizon. The first, of course, is the digital book, which eliminates the physical considerations of the "book" entirely. As I've written before, my daily go-everywhere Bible is on my phone along with a bunch of other stuff. The bulk is nominal at best. But so far, digital books are a disappointment to me, because while eliminating one side of the design tension, they don't yet offer full control over the other. The page isn't what it should be, even though it isn't constrained by the overall book. I expect this to change, but for now it's one of the reasons I prefer a "real" Bible to a digital one.
The second sign of hope? Unconventional thinkers like the folks at IBS behind the Books of the Bible project. You may not agree with every choice made, but they showed a willingness to privilege the page over the book. They didn't entirely escape the tension, but they approached the design problem from the reader's point of view, not the consumer's, and the more that happens, the better.
If I had to guess, I'd say inertia plays a big part in Bible design. Yesterday's compromises become today's expectations. Before long, if you don't set tiny rows of text in double columns with references running down the middle on bad, crinkly, five-o'clock-shadow paper with cheap gilding and a stiff pseudo-leather cover, people won't be able to tell it's a Bible at all. So an important part of the design process -- asking questions about how the text should be encountered -- can be entirely skipped over, the assumption being there are no solutions other than the ones that have already been tried.
There is, however, a small tradition of dissent. You see it not just in the Books of the Bible, but in The Message and in earlier formats like the single column NEB and in outreach New Testaments, and even the Personal Size Reference ESV -- anywhere the reader has been allowed to matter more than the consumer, the page more than the book. The NEB is the best for my money, the touchstone I wish more people were looking back at, but really none of these efforts is perfect. They still have to compromise. But for the most part, they tilt in the right direction, whereas too often the larger tradition points the other way.