Can you prove your wordings or have you any link which says like this? Never spread rumor as many altcoins already proved their value and established and investors first choice. May be some altcoins do scam after their ICO but not all altcoins are scam.
Here is the link to an interview he did yesterday where he clearly states they are all scams or 99.5% of them
https://www.youtube.com/watch?v=gsaSVf5YxfIWell, by saying 99,5% of them, he may not be far from the truth. We cannot but agree that most coins have been created just to enrich the pockets of the developers and we can count just very few coins that actually have a solid product right now, providing solutions and can easily stand on their own on the long run.
Most of the coins are just replica and they will end up useless in the long run as there will be no use for them with respect to the fact that they are just copy cats and there is no solution they provide that is not being provided already but I disagree with some of the coins he has mentioned though.