Why is a Provoked Urine Test so demonized by the Medical Community?

[Truth-Seeker]

I wanted to order my kit but then I saw that the medical community in the west is staunchly against using provoked urine test results as diagnostic tools for metal toxicity. The current evidence is against them and shows huge inconsistency in how much mercury comes out of people and that the "body burden" hypothesis of Mercury coming out with DMSA and DMPS is not true. 

The CDC, ACMT, and ATSDR are all against it. 

Leo must have seen this stuff. What does he make of it? Should we test metal toxicity with blood tests? What does the chelation detox community say about this?