they just haven't learned only when coins ICO could still experience a price increase even more than they sell. Yet many minded as long as the price is still high then it will be a good thing for them to sell before the price drops to the lower point. obviously just an opinion it is less precise because if you want to be patient and wait even then the increase will occur and could even reach or approach the value of ICO.
Well, actually people who have already made a good amount of profit from selling their previous share of coins decides to dump the current and certainly a very small share compared to their previous lot, at a very lower price so that other people cannot make enough profit like them and the price they are selling at becomes the market standard. That's very commond, right?