I have extensively researched pros and cons of giving it up, as well as done experiments on myself (going on and off, changing frequency, changing volume, changing diet around the coffee, etc.), because I am very health conscious, and don't like to feel I am "addicted" to any one thing.
So I hope I am not rationalizing based on my bias, but I see a wide distribution of research results (and anecdotal evidence like this article), so I think it comes down to the individual.
Certainly lifestyle, diet and health, but quite possibly specific to the genotype. We now know that specific mutations, alterations and combinations impact everything from how you digest (or don't) folates, gluten, sugars etc, and the impacts of all those (and more) on serotonin, dopamine and other neurotransmitters.
What is the possibility that we find the same for coffee/caffeine - that it impacts us each differently? Strong, from what I see.
And we know very few things exist as islands or vacuums...what about the myriad of combinations of genetics, environment, diet/nutrition, exercise, sleeping habits, type of work, emotional health, sun exposure, etc?
I know the above is not helpful to those of us looking for simple, binary "answers", but I am not sure those exist for something as powerful as coffee/caffeine.
If HN folks know of more research that disproves (or is at least evidence against) that hypothesis, then I would love to read it.