If your brother and friend pissed their lives away on pot, then---no offense---your brother and friend were, or perhaps still are, both pretty weak individuals---pot be damned. Blaming any sort of inanimate object for one's woes is the first step to a socialist mindset . . . wholly akin to the "guns kill people" line of reasoning used by our opponents on the left. It's far easier to blame something like pot for all your troubles than it is to take a cold, hard look in the mirror: it's a weakling's excuse.
Bad analogy. Drugs and specifically pot, enable and encourage a person’s “weakness.”
Unfortunately, exposure can happen at a time when we are most vulnerable. Drugs allow the person to avoid confronting the tough issues in life. Yes, life can be tough. But it is necessary for us to mature and move on to the next level and on to a better life.