At what frequency is visible light no longer yellow but rather orange? If that line is not easily defined, does that mean there is no difference between violet and red?
Discussions like this get extremely emotional and dialogue reduces to the lowest common denominator. Tragedy of commons is very relevant to the forming of morals. This is evidenced by hundreds and thousand of years of various abuse of humans. And while humanity is arguably in the best shape ever, there is uncertainty if we are heading to global or only a local maxima.
So no. Argument from community consensus is a bad heuristic for searching global happiness maxima. Of course, if morals are means to an end, not a goal in itself.
I wasn't trying to make a plea for community consensus. I think individuals come to their own conclusions about morality, but those conclusions are informed by the information that they receive from their environment and community. A person who never experiences meaningful debate, thought, or contemplation is going to be morally stunted compared to those who engage in regular debate and discussion. That doesn't mean every person who argues a point is morally superior, but in the aggregate, engaging in moral discussions will enhance an individuals expertise in determining moral veracity.
If you treat community discussion as a search for optimal morals, I fully agree with you. However, I stand by my original point as top voted comment already decided on the immorality of the JFK-Mimi affair as immoral without meaningful debate.
I think you are improperly comparing community consensus with tragedy of the commons. Community consensus is more akin to regulation than it is to nash equilibria. It's the nash equilibria that has been a bad heuristic for finding the global happiness maxima, because it's through the nash equilibria that the tragedy of the commons occurs. In contrast, effective regulation can better ensure the global happiness maxima. So that's why community dialogue and a rough consensus of mores can be useful and productive towards the health of a society.
So in other words particular people are unwilling to draw a specific line in the sand, but we nevertheless think that a democratic process is valuable?