The following is pure speculation on my part since I have no direct or indirect knowledge of the psyche of drug criminals. I have however come into contact with armed individuals of whom was unsure of "why" they were in the woods (ie not hunting or hiking).

My guess is if you did come across some drug criminals, they are 1. probably armed 2. probably more than one of them, 3. more "afraid" and trigger happy. Thus an unknown person who startles them will be met with a drawn (or visible) weapon in an attempt to scare them off. If the unknown person either had a visible weapon, or showed theirs it may escalate the situation and increase the danger. For me, the safer bet would be to not carry a weapon, especially visible and if an encounter happened, play dumb and tuck tail. back at the car I would then notify the authorities. In most cases an armed civilian increases the threat level of the situation and the likelihood of harm for the civilian, as opposed to the feeling of "peace of mind" that carrying provides. my .02cents only