I've had plenty of background checks. Not once have I ever been asked to provide divorce documentation. I've had security checks as well. Have I been asked if I'm divorced? Sure. Never have I needed to show someone the details of the divorce itself. It's not my employer's business who got what in the divorce.
So let's just flip this. Why have you been asked, and what were they asking to see? Proof you are divorced? Did you claim something that you were awarded by the judge and had to show proof of it? If someone is asking for that kind of information, did you not ask why they needed and get an answer? It would be much easier if you just explained your experience as it is the outlier here
You're the outlier - and the explanation is simple. Where you are, divorce and family court filings are part of the public record. A request isn't necessary, because the background checking org already can see the full documentation. They care to, because who you are in debt to, can influence you in future. And it takes about 3sec to confirm this, rather than sitting there saying "no, you".
Your employer enjoys your data without your say so [0].
EU, UK [1], Au [2], NZ... They have to ask. So they do.
But as you call it a "decree", and I only know one legal system that does (Texas), we're probably from different backgrounds here.