I don't know anything about the lasercomb or its possible effectiveness. I have never tried it and I don't plan on doing so, especially in light of its current controversy.
But, in my mind, what stands out more than anything else is Doctor Feller's confidence is his knowledge/opinion of the ineffectiveness of the lasercomb and his willingness to come forward, publicly, with free-to-see scientific data/rationale/experimentation, and to publicly debate the issue with lasercomb advocates/doctors. But there seems to be no reciprocity on the lasercomb side at all --- have they done a Criss Angel Mindfreak and disappeared on us?
I think Doctor Feller's sternness in his knowledge/opinion speaks to his quality as a doctor and care for his patients and literally all of us suffering with hair loss. His underlying message seems simple to me: "It doesn't work -- Don't waste our money!"