Meth dealer do not sleep. They stay up for days on end and become paranoid and have in the past taken pot shots out windows at neighbors they thought were watching them. Plus they tend to blow up the nighborhood.
Research meth addiction and see what the problem is. MArijuana deallerslseep meth heads do not. They get out and drive around looking for people to rob, rape, or just jack with.
Many dealers are smart enough not to use any of what they deal.
And, let's see, a meth user up all the time was doing so in an utterly darkened house. Makes sense to me!