@inthedark – I must admit that I haven’t really been able to devote time/thought to this topic. I’ll respond anyway.
I understand your point about the true meaning of what a divorce is and that it may not “prove” anything. However, in the vast, vast majority of cases, it is pretty clear that when a couple divorces they do so because either one or both are no longer willing to live a conjugal life. In other words, the marital relationship has “irreparably failed.” Also, even if it is true that divorce is not conclusive proof of failure, divorce is very meaningful (as you have made clear in your posts).
Regarding the requirement (post 2015) for this “irreparable failure”–this might not have anything to do with the in/validity of the marriage. The wording of the canon clearly avoids saying that the marital/sacramental bond has failed. [Not every marriage case receives an “affirmative” decision, even though the conjugal relationship has failed.] The “failure” is “such that conjugal living cannot be restored”, not that the bond has ceased or the sacrament has ended. I wouldn’t take this “failure” too ontologically, as though once it can reasonably said that a conjugal relationship has failed it is utterly impossible for that relationship to ever be repaired/restored.
Clearly, it takes only one of the spouses to make cause “irreparable failure.” Why is this a condition? I can’t say much more than what I said earlier. It goes back to Apostolic times: the Church wants to avoid contention and the nullity process is “contentious” (in the legal sense of the term, at least). If it is not clear that the Parties are no longer willing to continue their conjugal life, then the proper course of action is to try to remedy whatever might be preventing conjugal cohabitation. Practically, also, I would hesitate to compare a judicial process to the Sacrament of Confession.
The old law spoke of the judge trying to “induce” reconciliation/convalidation. I think a reason why this was dropped is that the Judge is an agent of the external forum. Much of the work of trying to reconcile a couple would pertain to the internal forum. It is best to maintain a distinction between the internal and external forums and having a Judge delve into both is not appropriate. Besides, it can sometimes happen that Judges aren’t the most well-trained/experienced in terms of pastoral care.
In your particular circumstances, you are always welcome to speak to a local priest and/or authority at the Tribunal to see how your own bishop and Judicial Vicar interpret and apply c. 1675. If you really want to pursue a nullity case without having a civil divorce, you might want to speak to a real-life canon lawyer to see what your options truly are. It is worth pointing out that c. 1675 does not mention “civil divorce”…