The petition is about doctors in the public system - in public hospitals and the like. They are talking about the distribution of scarce resources, ie taxpayers dollars, within that system. They are seeing the nurses and other hospital professionals, with whom they have to interact, being poorly paid, understaffed and overworked - and are simply stating their preference that those scarce dollars go elsewhere within their health care system for the benefit of staff and patients.
I presume that, as in oz, not all doctors are in the public system - their salaries remain market-driven. This is not about minimum wages anywhere... It is not about anything outside the public health care system in Canada. I am unsure as to whether the USA has public hospitals along the same funding basis, with (almost) free health care for all.
Democracies are based on utilitarianism - broadly, the greatest good for the greatest number. How they achieve this, eg big/small govt intervention, varies across countries and eras. Democracies are not simply about what the majority wants - governments have a role of governing for all, not just a numerical majority on any issue. A key role is the equitable division of scarce resources, including to health care, but the list covers so much more.
i for one applaud the Canadian doctors petition.
To the person who mentioned the steel/aluminium tariff - it's not just China! If it isn't softened, or targeted, your country will suffer economically (and in other ways) along with the rest of the world.