I think it's less about blame per-see, and more about the lengths they went to to fight back when they could have retreated. There's really no "two sides" when it comes to mass genocide and pogroms. The Kree set out to wipe out an entire species, and my inference from that line is that there were some Skrulls that fought more for revenge and spite than just survival, and the end result was only a million survivors where there could have been a billion or three.It implies the Skrulls may not have been 100% blameless in the Kree War. Sometimes there are villains on both sides.
Victory at any cost sounds like an inspiring thing until you see what is left when the cost is "almost everything". Nobody wins a war like that.