Taxing capital gains at a higher rate than wages will discourage investment in the stock market, and help lead us away from our addiction to stocks, an addiction which time and time again has led us to harmful cycles of boom and bust.
O Rly? Boom and Bust is due to the stock market (primarily...in other words, getting away from capital investment means no more boom and bust)...even Opebo's video attributes it to the growing and shrinking of the money supply due to the creation and retirement of debt.