Why should anyone who works a full week not earn enough to have a decent standard of living - whether they are lavatory attendants or neurosurgeons?
Yes - there needs to be a differential - but everyone is entitled to the dignity of a living wage. And are you really of the opinion that the only thing that attracts people to a job which requires qualifications is the wage? What about status? What about personal pride in achievement? What about interest in what you are doing? What about the comfort of a job which is conducted in a clean and pleasant environment rather than in a filthy and dangerous one?
Do you really think that if (say) the law was not well-paid, then all present lawyers would say - "Stuff this for a game of soldiers!" and seek out jobs as bin men?
And some of the most highly paid individuals in our culture aren't people who have slogged for qualifications - they are "celebrities" of sport and screen. A lot of these are paid a damn sight more than a lot of hardworking highly qualified individuals. Is that right or wrong? And what about all of the "Hooray Henrys and Henriettas" who are given well-paid sinecures) e.g. in "political research" during their university vacations - not because they are particularly good at (whatever) or particularly hard-working, but because of who their family is? How fair is that?
Paying people below the cost of living may be saving a company money - i.e. reducing the profits for the shareholders - but in terms of the country it is costing ALL of us, because if people can't live on what they earn, they have to claim benefits to support their families. They also cost the health service a lot of money because poor people are more likely to be chronically ill - depression, anxiety, and diseases caused by poor diet and poor housing.
There is nothing wrong with well-qualified, experienced people earning more than individuals in unskilled jobs - I agree there needs to be a differential. Doctors for instance, have a lot of responsibility heaped upon their shoulders as well as their surgery hours, and should be compensated for this, but we need the lower paid workers as well.
If the politicians all disappeared, one could argue that things would chug along pretty much as now; if all of the professional footballers disappeared, perhaps for some people their quality of life would be diminished, but we'd all get over it; if all of the the refuse collectors disappeared, the country would vanish under a mountain of filth very quickly.
Whose job is most important?