This is one of the prime examples of “just because it’s in the Bible doesn’t mean God approved; to the contrary.” It doesn’t always say “and this angered the Lord” because we are supposed to understand that without being told. Having a concubine, let alone abandoning her to be abused, is so far removed from “she is bone of my bone, flesh of my flesh” and the Love that God Is that it is supposed to stand out as starkly as it does to us. I don’t think modern people are removed from this behavior at all. Even in nations that are “at peace” internally, you have cruel criminals and crueler politicians perpetuating horrific evils every day.