Many of the "investors" are new to the crypto market and new to the finance industry in general. They have heard form a friend of two that there is a lot of potential in the blockchain sector, they heard about mining, about how BTC started and how much it's worth now, and they find this a reason enough to get involved into it. Most of them are looking for quick profits and don't really care about the underlying value of the coin that is being offered during the ICO, they are promised big returns and that is the main reason they are joining these sales. Actually most of the coins are crap and most of the investors are even crappier, so let them keep on losing their money and they'll eventually learn how this works. It's a lot of work to invest in good coins, people have to realize that.