Scam is a word that gets used too frequently in crypto and while I don't think Vays meant they will run away with your money, I believe it meant the projects won't exist in a little while from now. 99.5% is a bit on the high end as well but I agree with the over arching sentiment and that is most altcoin projects are essentially useless and 90%+ will not exist sometime in the future. Pick your alts wisely because nobody knows when the last run for those suckers will be.