I don't think the definition of addiction has to do with how many people are addicted. Seems uncontroversial to me that the majority of the population in the early part of the 20th century were addicted to tobacco smoking, for example.
Google brings up this definition of addiction: "physically and mentally dependent on a particular substance, and unable to stop taking it without incurring adverse effects." How widespread it is doesn't enter into it.
I think you're absolutely right that "addiction" has a negative connotation, and all things considered most people are less likely to pass judgment on things that the majority does. But people do criticize popular things all the time too.
Er, no, we started talking about nicotine addiction long before that.
> Back when everyone did it, it wasn't treated as an addiction with us blaming individual smokers for smoking.
Actually, treating it as an addiction has been exactly the opposite of "blaming individual smokers for smoking" -- while certainly the fact that it has become rarer has coincided with an increase in stigmatization (there's a two-way causal relationship there, in a positive feedback loop), that's separate entirely from treating it as an addiction (that's treating it as something people don't like around them.)
Treating it as an addiction is providing medical and counseling support for people to deal with the addiction, and placing blame on the tobacco companies for deceptively and knowingly marketing an addictive substance for many years.
> It was treated as a public health problem, and ultimately the blame was laid at the feet of the tobacco industry.
You seem to use "as an addiction" and "as a public health problem" as if they were opposites, which is odd, because actual addiction is (and is treated as) a fairly significant public health problems.
I've never seen a definition of addiction that uses "most people don't do it".
Addiction tends to require:
i) Tolerance
ii) Pre-occupation
iii) Seeking
iv) Continuing when you know it's harmful.
Obesity tends to lack the tolerance and the seeking behaviours.
Because 75% of the country doesn't have a moderate to severe coke addiction. "Addiction" is what we call behavior that falls outside the "normal range" on the bell curve. What the majority of people do is by definition "normal" and so when you have a problem that afflicts the majority of the population, the problem is considered structural rather than aberrational.