No, I don't think what I'm saying implies that. Being single isn't a sufficient condition of being moral. What I'm saying is that romantic love can be an impediment to being moral, which means removing that impediment might make it easier to adopt a moral perspective, but there could be other impediments. Indeed, just as romantic love might also provide a way into morality, as I concede in the article, being single might present its own impediments.
I'm planning to write another article on this topic, to push the argument further. So that might help clarify the problem. The problem isn't just romantic love, the intensity of which burns out eventually anyway. Instead, the problem is the tribalism that such love engenders. The key for me is the difference between narrow and broad perspectives.