lets use your 10% example.
A father of two who works as a factory brings home, lets say $1000 every two weeks, and he pays $100 to the federal government leaving him $900 to pay his rent, bills, car payment and put food on the table. He certainly can't afford to put braces on his daughter's teeth or even go out to dinner with his family. He is the representation of the working poor.
His employer, who is also a father of two is the CEO of the conclomerate that owns the roofing company that the employee works for. The CEO makes, lets say, $200,000 every two weeks (just pulling this number out of my a**) and pays $20,000 in taxes, leaving him with $180,000 to pay his expenses.
Do you think that is equal? The employee labors away to line the pockets of the CEO and doesn't have two dimes to rub together, while the CEO makes more than he can ever spend. I'd say it is not equal at all.