For an ICO to be successfull it has to provide a need or service that is not already available or deliver it in a better way.
The need now days of most of the coin that comes in the market does not exists actually. They just introduce the coin for their own benefit sake and think people will buy it and demand and price will go sky rocket and they will make it quick money. So many ICO and people are getting smarter as well to only handpick a good ICO coins only now.