Before you hate an addict, STOP. Think! Use your reason. You know that you've wondered about "these" people and why "they" can't "just stop" ruining themselves, doing drugs, committing crimes, lying, hurting you...
What makes a person want something so badly they will give up all dignity (in some cases) for tiny specks of powder, empty prescription bottles, no more glamor alcohol? Try to imagine that something must take over this person's brain and body, something like a kind of cancer that eats through healthy tissue and overtakes it thereby altering it at a molecular level.
There is a great deal of pain on all sides of addiction and while society tries to "teach lessons" via punishment the recidivism rate doesn't decrease. If this method worked the jails and prisons would be much less empty rather than overcrowding, but instead the only business the keep counting on despite a downward economy is corrections.
At the very core, I don't think that most addicts wanted to end up being what it is you're seeing. It's a spiral out of control. Out of control.