Cutler's view on testing is actually more nuanced than that. Yes he likes hair tests and wrote a book on interpreting them.

He also has a theory about how mercury fouls up movement--transport--of minerals in hair and the body thus making it more likely to result in statistically strange hair tests.

An early version of the theory is in this discussion with a noted autism doctor.
http://onibasu.com/archives/am/2200.html

Cutler actually likes symptom clusters for diagnosing chronic mercury poisoning. In his earlier book, Amalgam Illness, he has a chapter with checklists to help a person identify the clusters.

He thinks provoked urine tests of healthy people are not that well distinguished from tests of unhealthy people. So why take the risk of an adverse reaction to the test and not get back valuable information. He discusses this in his interview with Mark Schauss.
http://www.letstalkrealhealth.com/dr-andrew-cutler-phd-mercury-detoxification/

Remember the "normal" people used by the testing company to set the reference ranges were *not* taking a provoking, chelating agent! In a provoked urine test you are comparing apples and oranges.

I imagine doctors like those tests because if they ever get hauled into court, a jury won't understand the possible irrelevance of the high levels. They'll be convinced that the doctor was trying to help a sick patient with high levels of toxins.