Another problem for virtue ethics, which is shared by both utilitarianism and deontology, is (iv) "the justification problem." Abstractly conceived, this is the problem of how we justify or ground our ethical beliefs, an issue that is hotly debated at the level of metaethics. In its particular versions, for deontology there is the question of how to justify its claims that certain moral rules are the correct ones, and for utilitarianism of how to justify its claim that the only thing that really matters morally is consequences for happiness or well-being. For virtue ethics, the problem concerns the question of which character traits are the virtues.
In the metaethical debate, there is widespread disagreement about the possibility of providing an external foundation for ethics — "external" in the sense of being external to ethical beliefs — and the same disagreement is found amongst deontologists and utilitarians. Some believe that ethics can be placed on a secure basis, resistant to any form of scepticism, such as what anyone rational desires, or would accept or agree on, regardless of their ethical outlook; others that it cannot.
Virtue ethicists have eschewed any attempt to ground virtue ethics in an external foundation while continuing to maintain that their claims can be validated.
Your own link mentions some of the metaethical problems with the accounting for or justification of virtue itself. On a naturalistic world view, without simply presupposing it, there doesn't seem to be any way to account for any such things as for virtue ethics to be about. Why should the chance/necessity of physical processes that constitute the universe produce any such things as virtue or vice? What sense does it make to praise or blame physical processes for anything? If the physical universe is all there is, how is it that there could be something that is not as it ought to be, or is as it should be?
Cordially,
However, there are lots of people who don't agree with me.
Even though they don't agree with me on this point, there are lots of other things we can agree on: private gun ownership is a good thing, small government is a good thing, free markets are good things, abortion is a bad thing, etc.
We need to work with lots of people in order to get the working majorities necessary to eliminate bad legislation and enact good legislation. Why would we want to, right from the get go, eliminate all non-Christians from our coalition?
If I can get an atheist to support the second amendment without first convincing him that God exists, what is wrong with that?