Excuse me, but what I don't understand is why there is so much discussion regarding DxO Mark?...
It should also be clear that marketing statements ("image science"?) are sometimes contrary to actual fact. So please excuse DxO for publishing what managers think they should publish, because as a company they have any right to do so. On the other hand there is no reason to complain about this or that score being somewhat different from other tests or actual real life experience.
There is a lot of discussion because many people take them seriously, including somewhat respectable sites like DPReview. Luckily the latter carry out their own tests too.