"Physical dependence" with respect to addiction really is nothing. Substances that create physical withdrawal symptoms can certainly be very very unpleasant (even dangerous), but if they were at all the main factor in addiction, drug abuse treatment would be a glorious, happy, incredibly successful industry.

Think about it: Even the worst "physically addictive" substances, let's say heroin, will be completely clear from physically in 7-10 days. Two weeks tops. Anybody can put up with that and, in fact, many addicts do it all the time. If that was the differentiating factor, locking up an addict would work because they would come to their "senses" after no longer physically dependent. Obviously, that's not how it is. Real addiction is something much deeper and cognitively still mysterious. Physical withdrawal (those first two weeks of hell) is called, in the treatment community, the easy part.

I think when most people use the "physical dependence" reference like you did, they are really trying to categorize and emphasize (internally or externally) that among substances and behaviors that are addictive, certain ones more often consume a persons entire being. This process is still a complete mystery and even if people can't or won't accept the amazing power and bizarre scope of cognitive function...it is certainly not 'physical dependence' and I therefore don't think there is any real need to continue with that minor classification.