Why do Westerners espouse Judeo-Christian law but not Judeo-Christian morals?

Most politico-socio scholars have agreed the western governments are based on Judeo-Christian law and in op-eds defend it. But why not Judeo-Christian morals? Why keep some of Judeo-Christian philosophy and not all of it? "Thou shalt not murder" but yet America has in prison more murders than any other country; some of those murders claim to be Christian. Adultery, fornication, theft, abandonment of families, cruelty and abuse to orphans and institutionalized elders are rampant. Why does the west incorporate those laws found in Torah and New Testament as a base for their governance but don't practice the morality of them?