Re-read the post. SLOWLY this time. Greenspan addresses both, the tax on capital, and the elimination of capital gains taxes. Swing and a miss.
My point is that all three factors of production should be taxed equally: land, labor and capital. I don't like any preferences built in the tax code at all.
Greenspan is a Monetarist, or as I like to call them, Keynesian-Lights. I don't care for his monetary policy at all. And when he talks about fiscal policy, he is overstepping his authority.
I could find a quote where Greenspan doesn't blur the line between tax on capital and tax on capital gains if you like. But it is clear from the context that he is only talking about tax on capital gains.