In general desirability, a child-free environment is considered somewhere between smoke-free and germ-free. - Judith Martin

There is nothing to bring people together like a common grievance accompanied by refreshments.

Without such rules, there are no exchanges of ideas, only exchanges of set positions and insults. People who disagree rapidly move from talking over one another to shouting one another down, and from expressing their opinions on the matter at hand to expressing their opinions of the intelligence and morality of those who disagree with them.

If you can't be kind, at least be vague.