"The harder you work, the more you pay. How does that make sense?" Well, it doesn't if the high earners really were working harder but you cannot equate a very high income with someone working harder than someone who earns minimum wage. A very high income is the result of a number of factors but those do not include someone "working harder" than someone washing dishes or shoveling snow for minimum wage. Doing different work yes, but not necessarily working harder. Those doing the hardest work are often at the low end of salaries and may stay there their entire working lives. 
We all need to pay our fair share and yes, for those with higher incomes that share may be a little more.