[pcwalton]

I think that was more of a linguistic change than anything. If the word "addiction" had been commonplace during the lead up to Prohibition, I bet you that the prohibitionist movement would have constantly used the term "alcohol addiction", despite alcohol use being ubiquitous. Nowadays, for example, you see articles talking about "caffeine addiction", despite the fact that the majority of the population drinks coffee.

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.