Ultimately, anybody can choose to stop drinking coffee at any time. I know people who have tried to make that choice with nicotine and failed repeatedly.
I've seriously attempted to quit intake of caffeine about 6-8 times over the last 2 decades. In each case, I was able to temporarily quit, with withdrawal symptoms being more in the 2-4 week range. However, in each case, a small amount of caffeine at a casual event lead to intake of "normal" (for me) amounts of caffeine immediately. I would love to quit it (as I understand it's health consequences).
As a reference, I would say that I would be in the "heavy users" category with a daily intake of about 750-1000mg.
If you look at the sources the Wikipedia articles cites for its mentions of Griffiths, the National Geographic article compares caffeine addiction to heroin addiction and attributes to Griffiths a claim that as little as half a cup of coffee a day can produce physical dependence. The paper appears to agree, from the information in the abstract.