Chronic just means consistently for a long time, not the amount. There's lots of things for which chronic consumption is not bad (like pretty much everything considered healthy).
So if you drink 0.5mg of caffeine a day you're now a chronic user just as those who drink 300mg a day?
Sorry but that's bullshit. How can you draw any scientific conclusion without focusing on the most important aspect which is the dose of caffeine.
The word chronic alone doesn't mean jack here, when the daily does is all that matters.