The equity market tends to break down more abruptly than when it rises. The window to put on a short sale is very limited to say the least. Shorting against an uptrend or a bullish candidate is particularly dangerous.
It should be used as a supplemental strategy (eg, hedging) by more sophisticated investors.
One has to get into a much smaller time scale to operate. This is very hard for average traders. It brings about a separate series of problems: over-trading, rising cost on spread and commissions, and losing sight of the big picture.
You have to remain as calm, cool and collected as the African American guy from Goldman in the Apprentice show. But a guy of these superb qualities often fails to act quickly to cut losses.
Most average day traders go after high flying candidates for the sake of volatility. But one has to, first, understand how to manage volatility. The same could be said when it comes to leverage. What matters is not how many years you have traded stocks. It's how much edge you've gained.