I think I fundamentally disagree with your premise. I concede, I have seen communities where this happened . . . but by and large, they have been the exception rather than the rule.

The fundamental standard I have seen in communities that survived such things, versus those that didn't fall under two broad patterns.

A) Communities that survived were those where politeness was expected - a minimal standard that dropping below simply meant people had no desire to be seen with you.

B) Communities where the cultural context was that of (And I've never quite worded this correctly in my own mind) acknowledging that you were, in effect, not at home but at a friendly party at a friends house, and had no desire to embarrass yourself or your host by getting drunk and passing out on the porch - {G}.

Either of these attitude seems to be very nearly sufficient to prevent the entire issue (and seem to hasten recovery even on the occasion when it fails), combined they (in my experience) act as a near invulnerable bulwark against party crashers.

Now exactly how these attitudes are nurtured and maintained, I have never quite explained to my own satisfaction - it's definitely an "I know it when I see it" phenomena, however unsatisfying that may be.

But given an expectation of politeness and a sense of being in a friendly venue, but one where there will be a group memory among people whose opinions have some meaning to you, the rest of this problem seems to be self-limiting.

Again, at least in my experience - {G}. Jonnan