Why should DxO spend the, not insignificant, amount of time and effort, just to recreate what other dedicated tools do better already?
Simply because professional photographers need tools that facilitate and speed their work and it goes through a one-in-all interface usually called a Digital Asset Management (DAM).
When Lightroom arrived in the raw processing world it answered of the paradigm of the digital image process (ingest, sort, edit, index, process, catalog) . When Adobe changed their business model (standalone > subscription) lot of photographers headed towards an alternative (Capture One, Photolab, On1, Rawtherapy). All of them, except Photolab, do offer XMP support and more. No problem if DXO want to stay in an “one feature” category tool to claim the expert first place but please at least with no raw restriction format and with metadata IPTC/XMP support.
Now if the goal of DXO is to compete as a true alternative to Lightroom, sorry but there’s still a lot of work to do and the advantage of a strong know-how on image processing is not sufficient to convince photographer to migrate from LR to Photolab+PhotoMechanics (or other culling software).
Regarding the lack of support of all the Raw format it’s all the more surprising from DXO that had acquired lot of data from camera with DXOmark.
Thanx for your answer in french words 