Because drug dealers and criminals gain a lot of advantages from drugs being illegal. With drugs the illegal status opens up a black market trade and even ups the price on the retail end. read more
The advantages of drugs are there positive effects. e.g. Aspirin can reduce inflammation, ease a headache, reduce the risk of a heart attack. The disadvantage are there negative effects, in aspirins case it causes stomach irritation and bleeding, Depending on the situation what is an advantage to some is a disadvantage to others. read more