Great article in terms of calling out the sentiment, but their analysis is really dumb.
Just to be clear: the idea that sick days somehow impose a financial burden of the company is a blatant lie of criminal proportions. It is a justification for wage theft — the most common and most costly form of burglary in America. Sick days are part of an employees' compensation package; therefore, sick days are just another form of money owed to the workers. If a company is spending the money that it legally and contractually owes to a worker
Not only is this not accurate whatsoever, as companies are not required to pay you for unused sick time (thus making it not wage theft - also it isn't wage theft to complain - but the money isn't contractually owed at all).
What makes this truly bad though is that employers that do pay out for unused sick time see way fewer incidences of "sick time as general PTO," and workers actually get their full comp, and should be a standard across all employers. They literally skip over the thing that would be better for workers and employers, in their analysis.
If a worker wants to trade pay for time off, that should be their right. They should also be paid for the time off they don't take, as it is indeed factored into employee comp on the corporate level.