I think you’re exactly right. They are both unattractive traits. Whole groups in society may communicate with sarcasm, each trying to one-do the other. They pass it of as humor. Passive-aggression is hard to cope with because, if you try to confront it, the person who uses it, will deny it or not see it. Passive-aggressive people may not be at all aware that what they are doing is aggressive. They make excuses for their behavior.