You chose to take the first drink or drug, but no one chooses to become addicted. Sorry, that's just an ignorant statement. It's also not as simple as being able to choose to stop. Addiction is fucking hell to live with. If people could just stop do you think that would continue to live like they do in many cases? Addiction is a disease and a compulsion. You can just choose to stop being addicted the same way you can't just chose to stop being clinically depressed.
Do some research on the genetics and neuroscience of addiction before you make generalizing statements like that.