The point of that episode as I remember was that Randy didn't have Alcoholism, and was acting as though his enjoyment of alcohol was the same as people who do have an addiction.

Either way, I don't remember it too well cause I only watched it once as I didn't think it was a particularly funny episode. My advice to you is to remember that the point of South Park is to get reactions exactly like the one you just had out of people. They are certainly not above being contrarian or playing devil's advocate simply to get a rise out of people who take an issue too seriously. It's comedy, whether or not it gets a rise out of you is entirely in your control.