Not all capital gains are alike. To discourage volatility, I think short term capital gains should be taxed as ordinary income, but to encourage investment, long term capital gains should be taxed at a lower rate or even not taxed at all if held long enough (say five years).
STCG (held < 1 year) are already taxed like ordinary income. There are different gains rates for LTCGs depending on the type of asset...see a collectible vs. a stock etc.
I was aware of that, but the thread to that point had been about what to do in the abstract and posters had been treating all capital gains equally without regard to the length held.