If you look at any documentary about addicts (or hear real doctors talking about it), it's the step families are FORCED to take because every other method just results in the addict thinking they can continue.
"Being kind and loving isn't necessarily enabling."
If I tried to be kind to my addict friends and tell them in a sweet voice that what they are doing is hurting themselves, they would tell me to fuck off. People aren't stupid. They know that being addicted to Meth, Coke, or Heroin is shitty and unhealthy.
Tough love is the kindest and most loving thing you can do for an addict. It just might save their life. If they know that the result of being an addict will mean that you might not talk to them again, they will think twice about shooting up.