Because it is completely soul destroying and the negatives massively outweigh any positives?
I have a son too. I don’t think it’s so bad for men. I wouldn’t be so sad for him if he ended up having children. But I think for women it ruins your life and the happiest people I know - and I think some study confirmed this - are those that are child free by choice? Completely different if you want them and can’t have them I realise.