First of all, this is about an adventure, not the game rules, just to be clear on that.
Adventures can be heavy handed in their story telling or not, but what they always have to provide is some jumping off points / hooks for a story to happen. Depending on what hooks you provide, you nudge the story in different directions.
If you want heroes doing heroic things, fight evil and free the countryside, then goblin babies get in the way of that story. If you want to tell a story about the evils of war and the dangers of painting strangers as the enemy, then goblin babies might drive home that point. You choose your hooks based on the story you want to emerge.
You can ignore that and say ‘my campaign is simulating a world, goblins have kids, so there are goblin kids living in these caves’ but that still will affect the story that plays out at your table.
It’s one thing to wipe out a war camp, it’s another to wipe out a peaceful settlement that is just minding its own business, even if there are conflicts with the neighbors over who is allowed to take how many fish from the lake they share