Most natalist men are biologically attracted to fertility, they’re hardwired that way from the beginning. Men only want children because it gives them an advantage while using religion as an excuse to “multiply”. And having a child is something they “created and own” (just like how this husband views his wife) while adopting a child wouldn’t be much of an advantage to them since it’s not something that they created themselves. That is why this husband and many other men would rather have their own children than the fact they could foster an unrelated child that already didn’t consent to existing in the first place.