[Black Flag]

Having just reread the section on ethics and magic, I'd say it's pretty clear that the system as presented is intended to represent what is actually true in practice for most mages, not any kind of objective scale. That being the case, it's in keeping with human psychology that most mages would find the harming of non-human beings less of a problem than the harming of other humans. Compassion is intimately correlated with how much you consider the "other" to be "like you." And while the recognition of sentience in the "other" is certainly part of that equation, it's not enough by itself to engender compassion in most people. Many animals are demonstrably sentient and exhibit feelings analogous to ours, but the vast majority of humans feel little compunction against killing and eating them, wearing their skins, etc. Even among those that do find it wrong, very few consider it to be a crime of precisely the same magnitude as if it were done to a human.

The vast majority of spirits in the WoD possess limited sentience of the sort exhibited by animals. Moreover those that are wandering the physical realm are like beasts escaped from the zoo, not to mention potentially dangerous (and people are much less likely to feel compassion for something they consider to be dangerous).

Ghosts, like spirits, typically possess limited or no sentience, and even those that retain some semblance of a personality are still no more than soulless remnants (at least as far as most mages are concerned). And those are even more potentially dangerous than the non-sentient ones.

Vampires are unclean, possibly soulless remnants, too. And they are ultimately parasites, not to mention potential plague-carriers, etc. Even the most compassionate people have trouble empathizing with fleas, mosquitoes, and other parasites, due to an instinctual disgust for such creatures. Add to that the fact that vampires are extremely dangerous, cunning, and manipulative. And even they aren't always sure whether their seemingly human responses are genuine or just memories that help them to hide among the herd. Individual vampires can be sympathetic, but it requires a greater deal of trust and familiarity on both sides than is common. Rare, therefore, is the mage who would consider "wasting a bloodsucker" equivalent to murder. Of course, Wood provided for exceptions based both on familiarity with a particularly noble vampire and/or vampires' general ability to mimic humanity.

As a generalization, mages are still human and therefore exhibit typically human prejudices and moral failings, regardless of (perhaps even exacerbated by) the degree to which they believe themselves to have evolved beyond such limitations. Most human monster-hunters wouldn't bat an eye at killing non-human supernaturals. In this context, the only thing separating mages from the average mortal is that they think they're wiser, and that's not necessarily a good thing...