Because people are always willing to sell their ico coins less than what's on the market, the selling power will always be greater than the buying power unless in rear circumstances.
because those people that you have mentioned are investing without trust on the project instead what they trust is the profit after the ICO and nothing more
this is the problem if the projects are generics and no potential,the investors are only riding to profit and not to be with the team in future
so the main affected are the Hunters and those who want to stay holding
what also happen this days are the supposedly holders are selling right away when the coins are listed in exchange and this also made the new coins now dying and others are almost no value at all