There is a whole field of preventative medicine (also called population medicine) that aims to reduce the burden of disease.
Ever seen an advert for exercise? Seen warnings about levels of obesity? Seen an anti smoking sign? Received a vaccination? They are all driven by doctors, who aim to change behaviour to reduce the burden of disease.
There is enough disease and sickness to keep all the doctors of the world employed even if we were actually able to fix all the problems people currently have.
The major problem is, we don't have tools to fix the issues that are major in western societies: they suffer chronic diseases, and the problem with chronic disease is that they are very hard to treat (degenerative bone disorders, arthritis, emphysema and bronchitis, cardiovascular disease, neurodegeneration, diabetes and diabetes-related complications, many many others)
Don't drink the cool aid that has been thrown around... the problem is changing behaviour is hard - no-one wants to do it until they start suffering, and then it's too late. The idea that doctors are sitting there enjoying this windfall from patients they allow to get sick just so they can keep bread on the table is quite frankly extremely offensive and basely ignorant
"Making every contact count", a UK initiative to make sure that doctors[1] use every opportunity to promote smoking cessation, alcohol use reduction, weight loss, and other lifestyle adjustments.
Wow, that's truly the nanny state at work. I like tobacco, I enjoy smoking and I'm working on my weight. I hate it when I go to a physician's office and get offered the standard blurb about how smoking tobacco is apparently only slightly less lethal than mainlining cyanide with an arsenic chaser.
Frankly, that's a major reason why I don't bother going to see one. My body's working well enough, and while it'd be nice to know that my organs are in good condition, I don't want to deal with someone who doesn't respect me.
Why the fuck are you going to a doctor if you don't want advice that will treat your illness?
And this is the point: a lot of health problems are preventable, and it is your doctor's job to tell you how to avoid those health problems.
But then of course my comment was at least in part sarcastic. An advice can always be a good thing; on the other hand, my first reaction at the idea is to think that I'd like my doctor to listen to whatever health issue I have and solve it, rather than giving me paternalistic advice. As if we didn't have enough already.
Edit. Grammar.
You've never heard of preventative care visits? Annual physicals? Baby wellness exams? Vaccinations? I'm incredulous.
[1] http://articles.mercola.com/sites/articles/archive/2015/11/0...
[2] http://edition.cnn.com/2015/10/16/health/annual-physical-unn...