//Is that anyone's business?//
It most certainly is.
We are constantly being badgered and hounded over "environmental" concerns. Humans, we are told, are "destroying the planet". The largest single contributory factor to this alleged destruction is human population growth. Global population doubled in the last 50 years and doubled in the 50 years prior to that. There are now four times as many humans as there were in 1920. Prior to that it took over 100 years to double and before that it took almost 400 years to double. It is currently growing at more than 220,000 a day (over 80 million a year). Every one of these additional souls will require more space, more shelter, more food, more water and more energy.
Every day, from dawn to dusk (and beyond) , we are battered with propaganda about "climate change". I am often berated on here for my rather cavalier and often dismissive attitude to it. But believe me, problems which might come from climate change are nothing, but nothing, compared to those which continued excessive population growth will bring. But do we hear the BBC banging on about it daily? Are people gluing themselves to the M25 to protest against it? Hah.
If I said on here "climate change is nobody's business" I would be ground into the dust. Yet this pair knock out nine kids, increasing their existences more than fourfold, and apparently it is nobody's business but their own. So if that's so, it's nobody's business but mine how much space I occupy, how much food - and of what variety - I eat, how much gas, coal and other fuel I burn or how much water I use. I expect you'll say that my consumption of these resources is of general concern. So if I have a general responsibility to "save the planet" so do these two who have knocked out four times as many children as they really ought to have.