My stance on this is pretty simple. Everyone has something that hits that nerve. Something that has affected us in a deep, personal way, and that it is easy for us to get offended about.
For some of us it is alcohol and drug use. For some of us, it is politics or religion. For some of us, it is a particular member of the C's. For some of us, it is something more along the lines of the way people speak, or the way they act towards others.
However, as a mature adult, I personally think we all have a responsibility to recognize that not everyone reacts the same way to these things. We need to understand if something offends us, that does not necessarily mean it is an inappropriate discussion, and in fact, our negative reaction could have an even more negative affect on the discussion in general, and may cause more harm than good.
Or in the words of the great Adam Carolla, "If it doesn't make you happy, or make you money...then let it go!" And I have a hard time believing that complaining about people talking about drinking really makes any one happy, and it certainly doesn't make anyone money. Basically, all it does is create drama, and makes other people feel bad about themselves. So, why not just allow the people who enjoy the thread, enjoy it, and you can find a thread that you enjoy, and everyone will be happier for it.