I totally agree with you, bardegaulois.
What I am seeking to understand however is The Church’s definition of “manifest grave matter” - one of the things stated is the need to avoid public scandal.
As an aside and my personal thoughts only, it is far more important that the Community of The Church on earth understand that it is not their role to judge any person or persons at all worthy or unworthy where reception of Holy Communion is concerned in the instance under discussion. If one is troubled by the issue or related issues or anything at all, one can discuss it in Confession or by private appointment with a priest.
If a non Catholic perchance should comment that so and so are married outside The Church and receiving Holy Communion, the same thing should happen i.e. direct them to discuss the matter with a priest.
It does seem to me that the “manifest grave matter” rule in Canon Law opens up a whole can of worms and it has…a virtual Pandora’s box of confusion and non-understanding. It seems to me that in Canon Law commenting the need to avoid public scandal, it is also to keep The Church’s image ‘snow white clean’ and I think we already know where that kind of mentality might/could lead.