Normal when you're or went through similar. It's a way to download the rage you had for yourself into others, because doing it to you would catalyze your friend Ego. But beware, words have power. And if you say shit like that to a mentally-weak person, it can have serious consequences. So how about you shut the fuck up. That's completely unnecessary.
Couldn't have said it better myself. Everyone should keep in mind that junkies are people too and the causes of their situation are virtually always much more complex than just a moral failing on their part.