Because of how marijuana has been made nearly sacrosanct in some circles, they will not look at that THC or CBD as a contributing factor : (
Every honest therapist looks at all components of a patient's life, and the patient, too, has a responsibility to identify what is helping and what is hurting them, or in which situations a trade-off is justified.
We will never be able to arrive at a complete and perfect answer for everyone because people happen to be individuals. However the medical profession (including therapy professions) lean heavily on generalizations to avoid the overhead of having to deal with a living, breathing individual with a history and family context, where possible.
I guess what I mean is, nicotine is more self-contained than the others.
The problem is that it's a slow burn because it's consumed by smoking, and this is really the most pleasant way to consume it. People don't like the externalities associated with it, and that's pretty much it.
Perhaps the reason you don't see that is it is more difficult for teenagers to get alcohol. At one point in my life it was actually more difficult for teenagers to get alcohol than it was for them to get marijuana