Why (male) surgeons refused to call themselves Dr

The story involves a schism with GPs in England more than 150 years ago
Geir O'Rourke
Dr Michael Ee and Dr Amy Jeeves
Dr Michael Ee and Dr Amy Jeeves.

Why do some surgeons refer to themselves as Mr rather than Dr?

Debate on the age-old question recently surfaced once more after a hospital in Adelaide announced it was “phasing out gendered titles for surgeons” to help promote gender equality in the workplace.