That is true and tbh I'd rather have it right than fast.
I think you are right about the two type of utilitiies possibly needing very different information from Apple. The discussion that was linked to suggested as much. Its still been a long wait given that APFS support started in High Sierra.
I don't know how proprietary Apple thinks APFS is and what unique benefits it provides compared to other file systems, but when I ran a Product Management group at a high tech company we certainly would not provide internal design documents to any external company.
If the external company provided a complimentary product to ours that we deemed was beneficial to support our product sales and if we had no interest to provide that product or capability ourselves, we would create a "watered-down" document to allow that company to do the development, but the creation of that document had a very low priority.
I have no idea where Apple stands with all of that when it comes to APFS, but in the past I have seen Apple incorporate features into macOS where one previously needed software from a third party essentially putting that third party out of business.
Maybe Apple feels that they have built all the recovery mechanisms required into APFS and disk utility (or will when they have completed that development) and DW or the other programs are no longer necessary.
