There is no doubt that pharmaceutical companies make more money from chronic diseases than acute, curable ones. Infectious diseases is a good example. Fewer and fewer pharmaceutical companies are staying in the business of antibiotic discovery and production, largely because there is far less money in treating (and curing) an infection than in some other chronic illness like heart disease or diabetes. The majority of new antibiotics coming out, in fact, are for the infections with resistant microbes that require longer courses of therapy and are less likely to be cured. Not that that's a bad thing, becaue we really need those drugs, but that's how it goes.
It's true that diabetes is an endocrine disease, not a disease of the foot. However, good podiatric care is necesary for diabetics and we know it helps prevent complications. Diabetes, however well it is controlled by medications, will eventually break down the body, and it will affect the blood vessels and nerves in the legs and feet. There's just no way around it. Once that happens, any foot injury, no matter how small, can end up in amputation. An ingrown toenail can do it. That's why we recommend older diabetic patients to have all foot care be done regularly by a podiatrist. Including toenail cutting.
Preventative care has been shown in many cases to be much more cost-effective than waiting for complications to arrive. Organizations that refuse to cover preventative care have it all wrong and will end up paying more in the end.
Then again, I try not to pin everything on the big companies. Trying to get a patient to stick to regular preventative care is like pulling teeth. I'm sure there are a whole group of guys here over 40 who ran right out to get their prostates checked.