There's a fine line, as with alcohol. A single cup of tea might feel refreshing. A monster energy drink is going to feel like a fight or flight response. Some people are also more sensitive than others and some are addicted more really than others.
I guess I am a little bias here too - if my caffeine intake goes near 200 mg for the day then I get shaky. I have a friend who can toe the line at 700-800 mg! Which I read the other day that is the 'danger zone'.
Its an addiction, just like a lot of things.
So the article should be about how we are an addicted society to accurately capture the essence. You can be addicted to anything - good or bad or indifferent. And that's definitely the culture...