When btc dump, they dump
when btc pump, they even dump harder wtf
This easy to notice. Many new altcoins appearing daily. It's impossible that they all succeed.
However it is becoming more difficult to know which project it is going to be successful and which is going to fail since scammers are getting smarter and are trying to disguise their intentions and are doing everything they can so their scams look like something legit, this is why there are many people that prefer to stay away completely from icos and only invest in more established coins.