You're right that my comment was imprecise, in that I didn't specify to which societies it applies. I had in mind the modern Western societies, and especially the English-speaking countries. In other places, things can indeed be very different with regards to all the mentioned issues.

However, regarding your comment:

Moral sensitivity has nothing to do with (ordinary) actions.

That's not really true. People are indeed apt to enthusiastically extol moral principles in the abstract while at the same them violating them whenever compliance would be too costly. However, even when such violations are rampant, these acts are still different from those that don't involve any such hypocritical violations, or those that violate only weaker and less significant principles.

And in practice, when we observe people's acts and attitudes that involve their feeling of superiority over lower classes and their desire to distance themselves from them, it looks quite different from analogous behaviors with respect to e.g. race or sex. The latter sorts of statements and acts normally involve far more caution, evasion, obfuscation, and rationalization. To take a concrete example, few people would see any problem with recommending a house by saying that it's located in "a nice middle-class neighborhood" -- but imagine the shocked reactions if someone praised it by talking about the ethnic/racial composition of the neighborhood loudly and explicitly, even if the former description might in practice serve as (among other things) a codeword for the latter.