When the anger subsides, and thank God it does, it becomes clear that folks who suffer from addictions of any kind are not worthless people; they are sick people in need of help.
I don't like the word worthless. When I use it, it means that I believe someone is worth less than me. Every person deserves love, compassion, and respect; especially those who don't love and care for themselves.
It's important not to confuse compassion with codependency. I can have compassion and respect for others from afar, without compromising my self, my self respect, peace, and serenity.
Watching someone you love struggle to live with and then succumb to addiction is an eye opening experience.