That would be an entirely different moral case where negative, soul-crushing emotions are inevitable and justified. It wouldn't be solved by rewording the email to "in case you have kids". The least of your problems in such cases is mistargeted emails. The same emotion can be triggered just by looking at other people's playing kids or even from passing by a toy store.

What we're dealing with here is nothing like that. It's inflated egocentrism where one thinks that the whole world should respect their personal willful decisions, when no harm in any meaningful way is being done when they are ignored.