So I should be exempt from paying taxes because my salary is simply an appreciation of my education and experience.

This statement refutes their own argument:

"The taxes implicit in the asset’s after-tax earnings are already fully reflected in the asset’s price or change in price."

In other words when you purchased the "asset" it was known to you that any appreciation was taxable and therefore inherant in the price you paid and when sold you are well aware that gains are taxed and, to your benefit, losses are deductable. Using their argument against them would mean:

You pay $10 for a share knowing if it appreciates 10% you will owe $.15 in tax. On the other hand if you knew at the time of purchase that no taxes would be owed then you may be willing to pay $11 for a share.