But we're essentially in agreement hereRight, those are the kind of situations I'd offer only an apology for. Because there was no real harm done, and I personally don't think I did anything really wrong. Thus, I don't really understand how I owe them anything, and an apology is the only thing I can think of to offer. Real harm is something I'd try to make up for with money or equivalent services.
Well, I guess I see paying bills and appointments as promises, because I imagine what would happen if no one paid their bills, and the company went under. It's because I see the contract I have with the people I'm paying as being a promise... the most binding kind. That's really the only difference there. And I suppose I'd only consider being late to an appointment as immoral if I implicitly promised I'd be there... if I said, "there's a chance I might show up," and then didn't, I wouldn't consider it to be wrong.
So essentially INTJ morality operates outside the confines of politeness, which is why we come off as pretty terse and rude, but we take big breaches of ethics very seriously (especially if we're the perpetrators). That's also why I was shocked to find you thought we had no moral code.