This is right in spirit but wrong in letter:
The confusion is often stated thusly: “deontological theories are full of injunctions like ‘do not kill’, but they generally provide no (or no interesting) explanations for these injunctions.”
It's not a confusion it's just something that isn't true. Deontological theories routinely provide explanations for these injunctions and some of these explanations are interesting (though I guess that's subjective).
This is confused because the term ‘deontology’ in philosophical jargon picks out a normative ethical theory, while the question ‘why is it wrong to kill?’ is not a normative but a meta-ethical question.
No it isn't. "Why is it wrong to kill?" is a great example of a normative question! Utilitarianism provides an answer. So does deontology. A meta-ethical question would be "what does it mean to say, 'it's wrong to kill'". An applied ethics question would be "in circumstances x, y and z, is it wrong to kill?". Normative theories are absolutely supposed to answer this question.
Some consequentialists and deontologists are also moral realists. Some are not.
While I guess this could be logically possible, anyone who is not a moral realist needs to provide some kind of explanation for what exactly a normative theory is supposed to be doing and what it mean's to assert one if there are no moral facts. I say this as a non-realist who is pretty confused about what everyone thinks they're arguing over.
A moral non-realist can have moral theories in the "If, then" form. If you value A.B.C, then you value D.
If you're a paper clip maximizer, then ...
I think there’s a confusion in our discussions of deontology and consequentialism. I’m writing this post to try to clear up that confusion. First let me say that this post is not about any territorial facts. The issue here is how we use the philosophical terms of art ‘consequentialism’ and ‘deontology’.
The confusion is often stated thusly: “deontological theories are full of injunctions like ‘do not kill’, but they generally provide no (or no interesting) explanations for these injunctions.” There is of course an equivalently confused, though much less common, complaint about consequentialism.
This is confused because the term ‘deontology’ in philosophical jargon picks out a normative ethical theory, while the question ‘how do we know that it is wrong to kill?’ is not a normative but a meta-ethical question. Similarly, consequentialism contains in itself no explanation for why pleasure or utility are morally good, or why consequences should matter to morality at all. Nor does consequentialism/deontology make any claims about how we know moral facts (if there are any). That is also a meta-ethical question.
Some consequentialists and deontologists are also moral realists. Some are not. Some believe in divine commands, some are hedonists. Consequentialists and deontologists in practice always also subscribe to some meta-ethical theory which purports to explain the value of consequences or the source of injunctions. But consequentialism and deontology as such do not. In order to avoid strawmaning either the consequentialist or the deontologist, it’s important to either discuss the comprehensive views of particular ethicists, or to carefully leave aside meta-ethical issues.
This Stanford Encyclopedia of Philosophy article provides a helpful overview of the issues in the consequentialist-deontologist debate, and is careful to distinguish between ethical and meta-ethical concerns.
SEP article on Deontology