Why don’t we treat greed or pride with the same seriousness? It’s our social values interfering with our moral values. Something licit in society but morally wrong (like, say, blasphemy) seems less bad than something illicit in society while also morally wrong (like, say, violence in anger).

You can see this with the sin of lust. In some areas, society is sex-friendly and thus liscentiousness is less worrisome. In others, sex is condemned, and thus liscentiousness is elevated to be a killing offense.