Bigotry and intolerance are fundamentally irrational and illogical, so the so-called "left-bias" of science is just science being itself.
Now the comments in this HN page and the reason.com article are completely ignoring that, and only considering everything through a political filter.
Like what the skin color has to do with how good your physician is? Nothing.
Science is smart enough to propose the adequate metrics, in this case it does absolutely not include melanin.
Similarly, there is a body of scholarship that suggests that black physicians trust black patients more than white physicians trust black patients. If I am black, does the color of my physician matter when I talk about something hurting? The evidence suggests that it might.
The fundamental flaw in basing your moral philosophy in measurable metrics is that metrics are noisy and that noise will often undermine your point. Instead, you should be making a purely moral point: my doctor’s skin color shouldn't matter and I will act to make the world I live in more similar to this ideal. That moral point is the driving force behind the civil rights progress that has been made.
Your point is to use a proxy for the variable that really matters.
Unfortunately that proxy is neither reliable, nor has good impact on the society in general.
It is better to just use the pertinent variables directly without a proxy.
Your physician is good if e.g. they have also a research formation, if their patients are satisfied and have a good recovering rate for illnesses that promise recovery, etc.
PS: ok, I see that you also point to variable trust from the patient to the physician based on superficial criteria. I hope that can change in the near future when everybody has the mindset "the appearance is not what matters". The patients themselves will benefit from growing their openmindedness.