I am somewhat sympathetic and think there should be way more (decent) social housing. But I have (sadly) known quite a number of people have another kid to get a bigger/better home from the council.
A woman I knew had a little boy with her partner, and was renting a 3 bed private let. She got pregnant again when the little boy was 2, and moved into another private let - a TWO bed. Who the hell moves into a smaller property when another kid is on the way?
I spoke to her cousin, and it turned out she was on the housing list, and reckoned if they moved to a 2 bed, that the council would have to give them a 3 bed house.
Wrong. The second one was a boy too, and it turns out that they could share the second bedroom up to when the older one was 18.
You can probably guess what's coming next; a year later, she was pregnant again. I lost touch with her and her family soon after, so never knew if she was housed by the council or not. But she was definitely having more kids to get a bigger house/council house.
Not everyone does this, but some do. Like some women get pregnant so they don't have to go out to work. Sounds like a controversial thing to say, but it does happen.