People have been drinking/doing drugs since ancient civilization; the Egyptians were crazy beer drinkers (because of distillation, beer was much cleaner than their water supply), the Mediterranean civilizations had wine, the Celtic people had hallucinogenic plants, etc. etc.
I think it is part of human nature to seek habits that relieve stress and allow us to let down our inhibitions. And people crave to live without inhibitions, as countless people do things to their body that are obviously detrimental, and yet they keep coming back.
Now, im noy saying nobody should drink/smoke/do drugs, because its a personal decision, and in recreational uses tends not to be much of a problem. However, I know many people who seem to be unable to control their substance use. They have become attached to the false sense of freedom that comes with whatever subtance they use. This is when drinking/smoking/drugs become a huge issue, and when addiction and health detriments become a real problem.
Its a shame that some people feel they need to be completely wasted in order to have a good time, but that has been part of human behavior since the earliest of human civilizations, and there will always be that for years to come.
So i guess if your going to drink/smoke or do drugs, just try to use descression and good judgement. I really enjoy drinking and smoking weed with friends, but i never let myself get so out of hand that im putting myself or my friends into health risks, or becoming reliant on drinking/drugs for fun.
I think drinking/drugs can be a fun social activity, and abstaining from them can be a tough personal choice, but as long as your not getting completely wasted, the occasional substance use wont do any serious harm.