To be clear, all moral belief systems rest in certain, faith-based assumptions. I might even go so far to suggest that atheism largely amounts to putting one's Faith first and foremost in empiricism. I used to consider myself an atheist, until a friend asked me what I thought of Faith. In the process of explaining to her that I didn't have Faith, I realized I did have, but that my deity was of a different flavor. 20 years after that, I finally was comfortable to put a name to that Faith, although I still have trouble living up to the lofty standards of that Faith.
But I digress. It's fair to argue that ideologies tend to be one- or (at best) two-dimensional, whereas less ideological belief systems can live across all sorts of different dimensions, with different weightings and different intersections.
I'm hardly original in claiming that our values are much less our sense of taste--developed differently in each person, but with some common ground for most of us, and largely applied by instinct rather than by rational, empirical thinking. There's a whole school of modern psychologists who have largely confirmed that in the last 20 years or so.