For a long time now, people have used the catch-all term "Judeo-Christian" to describe broad strokes of social and philosophical ideas in Western society. This term is absurd, reductive and offensive, not to mention self-contradictory. This would be evident to anyone who has a proper understanding of the stark differences between Judaism and Christianity, both as cultures and as religious philosophies. The use of "Judeo-Christian" is an indication of ignorance and the willful marginalization of an entire people, while simultaneously suggesting some rather awful and incorrect ideas about many other religions and cultures.
So, what does "Judeo-Christian" mean in the modern context? Plainly, it is a term meant to represent a set of values that are supposed to be the foundation of the majority of Western society, especially in America. There are two problems with this assumption. First, the term suggests that the values espoused in Jewish philosophy are functionally identical to those espoused by Christian philosophy, which is incorrect. Second, it implies that values of other cultures are different enough to not even be mentioned.
While Judaism and Christianity have a lot of ideas in common, they differ from one another significantly in a number of vital ways, not the least of which is their disagreement concerning the sanctity and purpose of secular law. For a brief tangent on this subject, secular law according to the teachings of Protestantism (the most common form of religion in the United States) is divinely ordained because God is assumed to be perfect and active in the world, thus no state law could possibly be against the will of God. Law, as stated by Martin Luther, only needs to exist because there are those who do not accept Christianity, so it is a means to influence Christian behavior in a mixed society. Judaism, on the other hand, views secular law as something rising out of secular thought independent of God and subject to the same thoughtful examination as anything else in life. In Judaism, if a law is unjust according to Jewish philosophy, Jews should strive to correct it.
But these complex arguments seem immaterial when considering the exclusionary implications of "Judeo-Christian" as a concept. Not only are Judaism and Christianity fundamentally opposed on many philosophical issues, the term also implies that no other religion shares enough values with Judaism and Christianity to be included in the concept. It implies that, for instance, Islam, a natural outgrowth of Judaism and Christianity, is too different in its core values to be included in that social idea. This despite the fact that the core values of Islam involve belief in one God, acts of charity and study of the Bible. I'm not suggesting that the phrase ought to be changed to "Judeo-Christo-Muslim", as that would suffer from the same inaccuracies as the original term, just that it's insulting and incorrect to imply that the core values of other major faiths differ greatly enough from those of Judaism and Christianity to be excluded from the idea of fundamental social values.
The truth is that people in our society use the term "Judeo-Christian" to mask their true intentions. The "Judeo" part of it is meant to employ a sense of plurality to the unnamed values in question, to soften the idea of Christian values enough to make them seem universally accepted in countries like the United States. In doing so, the term reduces a nuanced philosophy to a footnote in our culture's dominant religious force while building a wall around the majority to exclude the very thoughts and ideas of the myriad minorities.