Relationship Anarchy

A benevolent interpretation would be indeed that the author of the original critique doesn't get the distinction either, which makes it somewhat ironic that they call what they criticise an "infantile disorder".

"Morality" describes what deeply held believes about right or wrong an individual has, often with religious undertones. Projecting those on others ("moralizing" a matter) that might not share these believes is what the original original critique is mainly about.

"Ethics" on the other hand is about an agreed set of behaviours in a community, because the community members believe this is for the better of all members of that group. Often it overlaps with what individuals in that community believe to be morally right, but it doesn't necessarily have to be so. In a way it is a method of consensus finding and not about projecting one's convictions onto others.

I am not deeply into the wider debate of the original critique and the response, but my impression from reading these two articles (only) is that the original critique's author is advocating for personal liberation against the "couple in the head", while the group they criticize goes one step further and thinks about community ethics that might prevent children from growing up with these false notions and then having to painfully unlearn them.