There's the difference. These people apparently DO make a habit of asking for, even expecting, help from the members of their church. Plus, while it's likely there will be volunteers, more children makes it harder on the volunteers; probably fewer step forward each time.
Frankly, it sounds to me as if they're taking advantage of others' good will. What's wrong with planning ahead? Line up help before you need it? Arrange for rides for the children and visits for the mom in advance - even before you get pregnant?
You said it better than I did a few pages back. This is what I was trying to say. Everyone needs help ONCE in a while, but when it becomes a habit it can be planned for and isn't unexpected anymore. If these parents want to keep planning these pregnancies then they should also plan and pay for the care of their other children not "depend on the kindness of strangers" so to speak. If they can't pay for the care of the children they already have then it is irresponsible to keep reproducing.