The problem with discussing morality is that we each bring our own moral systems to bear, then use emotionally charged words like "right" and "wrong". This leads to people at first disagreeing, and then arguing past each other. Doubly so because you feel like you have made a real point when you agree with yourself, while the other person feels like you haven't. And vice versa.

As a result I only want to discuss morality with people who either largely agree with me, or who are able to take a step back from their own moral system to discuss what someone else from their moral system might think.

By contrast laws and human behavior are external and hence easier for people to agree on. Yes, they are dissatisfying because none of us entirely agree with the law, and laws are deliberately vague in certain things. But I find that discussions of them tend to actually work out better.