I think that many addictions can be ok, so long as you understand how much power they have over you and keep a wary eye on them.

An addiction can work well in some environment but completely destroy you if your environment changes.

Also, I'm not convinced that caffeine addiction is completely overcome in the week or so it takes for the physical withdrawal. Even for myself when I decide to go through long periods of decaffeination, I find that my energy and motivation is significantly deteriorated from when I regularly caffeinate. Sometimes I wonder if my regular use as a college student permanently altered my brain chemistry. On the flip side, maybe this use set me up for the early career success that I might not otherwise have achieved.