"it is just that" is usually used as a polite way to disagree with what other says, or to politely say no to a request.
Is it idiomatic that one uses it for adding an extra point to what one just mentioned.
Group A require intentionality for moral act, group B don't. So the act described here is moral according to both A's and B's view. It is just that "intentional moral act" is not a proper term in the view of group A, because in their view there is no such thing as "unintentional moral act".
Is "it is just that" used idiomatically in the above sentence. If not, what to use instead?