themodelplumber is a perceptive observer of human psychology, and they've described some of the ways people justify cheating with one narrative or the other. This isn't advocating for cheating or plagiarism, just hypothesizing why some brains are happy to do it.
People have to justify bad things otherwise they wouldn't do them. This is how we get racism, antisemitism and discrimination in general. A lot of taboo activities have an initial moral barrier and once you break it there is nothing stopping you from doing it over and over again.