Trading is a risk. It's always stated only risk what you can afford to lose 
else you could put money in mutual funds. But even mutual funds are risky. So why not take some more risk and earn more profits which in trading could be earned if good techniques are used.
mutual funds are less riskier then trading , either mutual funds or trading controlling risks is up to trader , investing or anything will have risk we should decide which suits us and our risks to handle and go on , the safe way we search to safe risk the less reward we get else you could put money in mutual funds. But even mutual funds are risky. So why not take some more risk and earn more profits which in trading could be earned if good techniques are used.