No, the doctor's license is to prove competency in your studies as an award after years of theoretical medical school and internship at a hospital. This allows any employer to know with a quick glance that this person passes. Second, all countries have some sort of medical board that decides standards for licensing and ability to work.
New age medicine is proven by anecdotes, which is one of the weakest types of proof and evidence. What happened to standards and quality? THE LICENSE is there to prove standard and quality.
I would always pick a piano teacher with an ARCT or Bachelor's of Music over a piano teacher with no certification. If there's 5 teachers out there for hire, why not pick the most impressive one?
I would also not risk picking a doctor, dentist, lawyer, optometrist, orthodontist, etc. without a license because I don't want to get screwed over by an unlicensed practitioner and then not be covered by insurance or have leverage due to their unions.
Honestly, I don't know what kind of mindset you have to believe that licenses and certification aren't necessary in ANY job just because of an article that is more than 10 years old at this point WITH no cited sources or previous research articles referenced. Your linked article is an opinion piece with facts by a qualified writer (excuse the irony), but in no way would that article be published in any academic journal due to the lack of requirements it fulfills.
I am already trying my best to be civil as someone on the side of teaching.