Like others have said, that doesn't really matter.
Realistically, though, that is not always the case. Not only are some people born into the harshest conditions where drug use is (often violently) encouraged, but some people are forced into drugs through sex slavery. You also have to recognize that desperate people do desperate things, and even though it seems stupid to you, you don't really know what they are going through or what lead them to that situation. On top of that, you also have people who are prescribed addictive medications that lead them to addiction.
A lot of the time, it's horrible circumstances that leads to addiction, and though you may lack basic human empathy, you have to logically realize that you, too, are part of the society that enables that sort of circumstances that lead to addiction and crime.