The purpose is not to have a fictional work as some basis for deriving morals. Rather, it is to test our moral sense in extreme conditions, to see how it react

The purpose is not to have a fictional work as some basis for deriving morals. Rather, it is to test our moral sense in extreme conditions, to see how it reacts, and to see whether the theory we have still holds up. As an example, consider theft. As a society, we have a strong aversion to theft. This aversion is enshrined in our laws, our religions, and even our grammar (e.g. "my pen" as opposed to "your pen"). So, we would consider "Do not steal." as a general moral guideline, functional in all scenarios. But we haven't tested it in all scenarios. Let's consider somebody who steals for the purpose of helping another, commits no other crimes, and dedicates his life to helping others, even when it harms himself. Would we still consider the theft to be immoral? I would say no, and showing such a case is the primary purpose of "Les Miserables". We have pushed our general "Do not steal." outside of usual usage, and have found that it does not apply at extreme cases. Similarly, the author of the article is saying that Rogue One is a good test of the existing moral principle "Do not build intentionally flawed buildings." This moral principle works in most day-to-day cases. However, in the case of building a Death Star for an oppressive regime, this moral principle may not hold.