The writer wants to use the curve as a policy tool, not just worship the obvious relationship shown by the curve.
The writer did miss the most powerful example of using lower tax rates to raise revenue and business velocity significantly. When the capital gains tax is lowered, many investors use the opportunity to sell when they would otherwise hold (or in the case of real estate, use tax-deferred exchanges). The resultant sales raise revenue from each investor from zero (if prop not sold) to whatever rate has been set. This also causes consumption and job growth as new owners tend to spend to improve properties. Also, properties
being readied for sale often get improvements at that time.
Also, sales generate idle cash which is used for new investments, or deposited in banks where it is loaned to others so they can do or grow businesses.
The old ripple effect.