Do you have a citation for the "caffeine is healthy" claim? This seems like rationalization to me; as a non-drinker of caffeine, coffee seems like the number one legal drug in the Western world.
There is evidence of a bunch of mild benefits (and also mild risks). I'd currently say it looks like a small net benefit, but with a confidence interval that would include negative territory. In general, it seems reasonable to drink coffee if you like it. It certainly is an addictive drug, though.
Caffeine has been relentlessly studied for evidence of ill effect and, as you know, science publishing is biased toward positive results (so expect to see one positive p=0.05 outcome for 20 studies of a non-effect). I suspect that the puritan streak in our society which suspects that anything we enjoy must have an underlying evil plays a role.
In any event, the evidence of the ills of caffeine is so poor as to suggest a smattering of false positives. The studies showing positive effects should be viewed with similar skepticism, although if it does have some role in preventing Alzheimer's surely that's enough on its own.
It seems to me hard to really say whether caffeine is healthy or not. Rather the modern western lifestyle -- a lifestyle we've agreed to, or accepted, for the most part -- that has very little to do with biological rhythm needs to be evaluated for its health effects. As long as we're going to accept that everyone is going to work long mid-days in unison, sleep 8 hours per night, in unison, etc: then we're going to appreciate aids (fluorescent lights, caffeine, heaters, air conditioners, melatonin, food) that help us conform with everyone else.
Some may not feel they need caffeine as much as others: so be it. But the idea that any of us can really be deemed healthy or not, due to whether or not caffeine is part of the diet, seems to me to lose the forest through the trees
