i mean, if your idea of "having a life" is working a 9 hour night shift and then going home and smoking an ounce of pot during the daylight hours, or waking up at 6 am and drinking and chain smoking until you pass out at 8 pm, then that's a very sad reflection on yourself and a very sad reflection on society, as a whole.
these are people that do not have lives worth living at all, which is perhaps why they need to numb it with substance abuse. that's very sad and all.
but, i have every right to demand that their destructive habits don't affect my own life, or the ability to accomplish the goals and tasks i've set myself to accomplish within it.