Its not a mathematical problem that you just compare the curves, some problems are hard and cannot be generalized.

And you are adding other factors if you think people who do not want kids are somehow the outliers. Same as if people wanted kids might be if you actually looked closely, for most people its not a very well thought out choice.

Does the experience of the Outlier not matter because it is not the regular experience?

If we take outliers into the account, then any statement ever regarding human behavior would be false.

Any general statement.

Would that be bad? How?

So you're saying that people who don't want children in fact should have children to be happier? What a presumptuous thing to say.