Perhaps your houses have become dilapidated and rundown because of low quality members or mismanagement, but I wouldn't try to blame substances like alcohol for that result. Drinking, whether done by underaged or legal members of a house is a problem that needs to be addressed equally throughout the universities. What's the point of coming down with policies on one group when another or the entire non-greek student body can do it without question? This is the problem of enforcement of the one-sided policies.
On top of that, it would be wiser to teach people how to become responsible around alcohol rather than scold them like little children and slap them with fines. Obviously if they are going to do it, then the next step in curtailing the danger and harms of it would be to educate how to prevent problems and promote safety.
My whole point is that while drinking underage is of course illegal - you can't stop it. Do the next best thing, accept the reality of the situation and show students how to manage things and keep everyone alive.
It's just a little ignorant to assume all the problems of poor quality members comes from social activities with alcohol. I've known some pretty horrible houses that ran on substance-free activities. Bad members are the result of environment and probably a bunch of other multiple factors. Guarantee you that even without alcohol houses would still fall apart
RUgreek