There are many reasons behind the crash of the ico thats why the investors got tired, the reason is that most of the investors, especially the big investors, turns out that they make money in ico for a living. So when the ico got in the first exchange it is totally crashed due to many investors dump their coins.
You are right, most investors sell their coins immediately after entering the exchange. But they do it not because they do not have enough money to live. Look at the state of the market, it has been falling for more than six months! Investors are trying to save their savings in bitcoin or fiat currencies. But as soon as Bitcoin changes the trend, soon new money will flow into the ICO!