I agree addiction is an inappropriate term. There is however, as with all spiritual pursuits, a danger of escapism. One generally doesn't wish to escape from "the truth" (about the war on drugs, the banking system, environmental pollution and so on) but there may be a tendency to neglect practical matters, educational pursuits and personal relationships.
I mean, if you're going to trip twice a week, will you still have enough time to keep your house tidy, pay your bills, work out, cook yourself a decent meal and do your laundry, dishes, groceries and repairs? You may if you're unemployed, don't have family members and don't go to school or university. But as soon as you take on some basic responsibilities, time for serious tripping is naturally going to be limited to a couple of times a month, if you're lucky.
So whenever someone says they're tripping several times a week, it simply means they either have the good fortune of not having too many responsibilities yet (like we all did when we were younger, or later in life when for some legitimate reason we end up living on welfare or decide to renounce everything and go live in a forest) or that they are purposefully skirting such responsibilities, which would make their use of psychedelics a symptom of escapism, dysfunctional behavior and possibly immoral sources of income.