Well if you want facts, here are some you might find interesting:
(at the time of writing)
1) There are 1,545 coins/tokens listed on coinmarketcap.com
2) The cryptocurrency market cap is currently at $489,379,690,258
3) The top 100 coins/tokens alone (6.47%) account for $469,263,573,711 (95.8%) of the total cryptocurrency market cap
I know this doesn't mean that the bottom 93.53% are failing, but it's no secret that they're far behind. A large majority of them could fail and no one would notice. His prediction may be overly harsh, but I'd say it's not too unlikely.
I just check the coin market cap the the top gainer coins/tokens are those not belong to top 200. The 95% prediction of altcoins to fail bit harsh.
As long there are many altcoins and investors are invested on it, it will prevent the the BTC price to soar high in unprecedented manner.