Devil's advocate..

[Angrboda]

I assume the point you were trying to make was this - morality, like food, is a matter of subjective preference - that you pick one based on what feels best to you - and making one choice over another doesn't make much of a difference. So rational considerations have no place in the decision. The rest of the argument applies only if this is correct.

I didn't say that. It was an example of misapplying rationality. Morality isn't subjective preference but it is contingent, it matters where and when you live what morality you will end up forming. What culture you inherit cannot be predicted by a rational analysis and it's from there that the values which you would apply your rational considerations to derive. There is no universal platform because where you are born is purely arbitrary, thus the morals you end up forming have an arbitrary basis. It's like religious belief; the best predictor of religious belief is where you are born. Any attempt to apply rational considerations to which is the most reasonable religious belief will generally be futile (again, this is an analogy, nothing more; don't over-extend it). The rest of your post goes back to trying to establish rational standards where there are none by sneaking in a value statement as if it were universal. Morality works at a subconscious level; we don't choose how our subconscious reacts.