For a child to navigate this plethora of diverse opinion, they must develop a critical approach to the subject area. They must learn the concepts and language of that area and engage in the "agreed" and "disputed" interpretations of those concepts and terms. In so doing, as they sift through the various arguments, they may come to a position themselves and be able to defend that position.
A critical, secular education ensures that they are free to keep, or change, their position. Ethics teaches them how to dig through the various possibilities, including both religious and non-religious possibilities.
In a pluralistic world, children will continuously face questions relating to religion: Why do Muslims pray five times a day? Why do some religious people claim that the earth is only 6000 years old? Does God exist (or not), and if so, what is the nature of such proposed (or deposed) divinity? Why do Hindu gods have so many arms? What do they symbolise? What do equally ethical theists and atheists disagree on? Does China have a religion? When were the stories of Jesus written - by whom and why? If the Buddha was just a man, why do people call Buddhism a religion?
The value of combining ethical enquiry with a study about religions and philosophy in a professional classroom setting is that these questions can be examined in a way that does not indoctrinate or denigrate. For a child to agree with or disagree with Confucian values, they must first understand what such values entail, how they are applied by Confucians and what the consequences are for living a "righteous" life according to those values.
Respect and tolerance for others are empty virtues if a child knows nothing about those "others." Segregated learning is outdated and unenlightened.
Adding Primary Ethics as an alternative to Religious Instruction, on the same terms (taught by volunteers working outside of the authority of education departments), obviates the government's accountability to its citizens. It taints the ethics classes with the same "unprofessional," "unaccountable," "segregating" brush. Ethics deserves a better place in the curriculum, as does a general religions and philosophy subject.