I think you are right about that. There are no (or very few) actual physical withdraw symptoms with pot, while they are definitely present with alcohol in a true alcoholic.
However, that psychological addiction is extremely powerful. Extremely. And with pot legal and freely available, I would say that the bar to quitting pot just got raised a significant level for pot-heads.
Also, the very fact that pot is not “physically addicting” (or at least seems not to be), makes it very easy for a truly psychologically addicted pot smoker to convince himself that its easy to smoke “just once in a while”, where a true alcoholic, once he faces reality about himself, accepts more clearly that he must quit drinking completely.
I’ve seen it. The daily users always seem to have to have their morning wake-n-bake.