Is charity to strangers virtuous?

In a recent podcast, you answered the following question: "Does providing voluntary, non-sacrificial help to innocent, unfortunate poor people qualify as virtuous? In a free society, would such charity be a moral obligation?" You said that it's not a moral obligation, and I agree with that. You also said that you think it's a "great thing to do." But why? I'd evaluate it as such if the person you're helping is a good friend or a close relative. In that case, the act would be an expression of integrity, or of loyalty to one's personal values. But I don't understand why it's a "great thing" to provide charity to people you don't know, even if you're contextually certain that they didn't bring their hardship upon themselves and you don't view it as a moral duty. I'd think that such an act is morally neutral, or at best slightly positive. Can you explain your evaluation a bit more, please?