It's because alt coins can give you a potential ROI of 100% to 300% in an instant if you follow the trend, but like wise you can simply lose your investments in an instant. Stocks and other traditional investments are good also but don't expect much profit in very short period of time, You can't increase your position in stocks without taking money from your pocket or doing trades. In ICO you can increase your chances of winning by doing bounty campaigns as they can give a additional coins..