Does the aauthor of the thread get what he is playing? I mean the set and so on? There are plenty of games that don't are based on wars and fights between diferent factions (wheter they are races, social classes, or a bit of both).
This is a game based on a tabletop game wich is inspired by a subset of narrative called fantasy, a set that has its root in medieval european history (something a lot of people tend to forget, lets take for example tha so called afro haircuts post).
Ok, medieval ages weren't the dark ages certain narrative would love to be.
Nevertheless those where centuries in wich every and each population saw other nationalities as different and somehow less worth of living. So many wars, so many massacres and slaughters, so much prejudice, some prejudices against some ethnics groups saw light in those years (near the end of the Middle Age started the prejudice against Cinti and Roma, not to forget the emargination of Jews ), no matter how much we want the setting to reflect our modern values the fact that medieval ages were violent, full of prejudice, didn't care for lives of children remains.
Also in the game you play a role of a character that belongs to a certain faction, with their ideas and prejudices, not to forget, as I said in other replies, that Larian plays it in a subtle way that is if the player takes the time to talk to the goblins, specially the kids, to massacre them has a different taste, more bitter and maybe even a little rancid, the main characters and companions become more nuanced and there's no side that can be labelled as completely good or evil. I don't know if Larian did this in purpose, however to me is an amazing fact and shows how Larian doesn't ignore the ethic and moral values of our modern society, even if they don't do it in a explicit way (as I said to consider Goblins something more than cannibal pillagers there is the need to talk with them, adults and children).
On a last note: we have two paths, save the thieflings (killing the goblin leaders, and as far as i got reading the forum there is a strategy that allows not to slaughter all the camp), or save the goblins (killing the thieflings).