Because people see the explosion of crypto in late 2017. Many ico created to take away the money that investors entered. They see that many people will join their ico and they will play tricks on people's greed
Scammers always come at any time, this is what makes the market red, I'm sure when they get crypto they immediately sell to fiat so that the price drops.
Of course that would be their practice because they would not keep it in an exchange, They convert it immediately to fiat and leave the market, although some of these scammers are still among those making investment, some of them still end up being the whales too with the amount of money they have scammed from people.
ICO market has already been polluted, so I think the most focus of people now, especially investors is on IEO projects, at least we still have some faith in IEO projects based on the judgment of the reputable companies that carried out the project for the public to buy into.