If knowledge implies justified belief, as is traditionally supposed, then skepticism about justified moral belief implies skepticism about moral knowledge. However, even if knowledge does require justified belief, it does not require only justified belief, so skepticism about moral knowledge does not imply skepticism about justified moral belief.
What such practical moral skeptics deny is that I always have reason to do what is morally required. In other words, they deny that I always have reason not to do what is morally wrong. These claims are equivalent because it is morally wrong not to do what is morally required. Practical moral skeptics do not deny that there is sometimes reason not do what is morally wrong. After all, some wrongdoers are caught and punished. However, practical moral skeptics can still deny that there is always reason to do what is morally required or to avoid what is morally wrong.
Is there a practical moral skepticism, of the latter kind in the 2nd quote, that's skepticism about the truth of reasons for being moral?
So that we're justified in saying that everyone should always be moral, yet this claim isn't true. I think this would mean that, in practice, morality is justified but grounded (?) in something like a lie.
Seems possible, maybe even that realising that moral behaviour can be based on a lie is, in some sense, an important existential moment, that e.g. should not be done away with