The problem is in many cases, that various injuries can interrupt the function of the nervous system, and in particular, the sensation in the stomach that “turns on” the flow of acid. When this happens, any and all types of bacteria have an open door to the blood through the intestines, and can bring on problems like arthritus, bronchial congestion, type II diabetes, cognitive disorders caused by infection of the substantia negra, or other parts of the concavity of the brain, or of the basal ganglia, which can cause massive neurological disfunction anywhere in the body.
Digestion is the gateway of the immune system.
The only 'original injury' the infection hypothesis needs is an infection by some bug that simply turns off the immune system. There's proof that gliding bacteria can do this with capnine, and that gliding bacteria are wide spread. Once the immune system is off, you are prey to the common infections such as Borrelia, Babesia, Bartonella, as well as whatever is being coughed up the folks around you.
The term 'various injuries' would have to be more well defined for me to judge whether or not these injuries are common enough to cause anything like the diabetes epidemic we are seeing.
And, in any case, the betaine hcl is preventative, not curative, once an infection has settled in.