I forgot to mention in my first post that it seems that low stomach acid can produce the same symptoms as too much acid (i.e. heartburn, GERD, etc.). As a result, many doctors react to what they perceive as an obvious case of "too much acid," and prescribe antacid based medications. I also wonder about a possible connection between low stomach acid and Osteoporosis, since the body is incapable of absorbing calcium when acid levels are too low.
Regarding "Big Pharma," I agree that there's not much profit potential marketing stomach acid supplements which only cost around $10 a month. But I wouldn't be too critical of doctors on this issue. My physician is also a friend of mine, and a really good guy. When he diagnosed me with IBS about three years ago, his primary advice was to use occasional doses of laxatives as needed, and he shrugged his shoulders and told me "we really don't know what causes it." I think that's probably true for most physicians, and in fact, is why I'm scheduled to see him later today to share with him my recent discoveries.