He is correct that Crypto like currencies or commodities are not investments. These are speculations. He is wrong by not throwing a small percentage of his portfolio into the speculation. Speculation can be profitable by playing the mismatch in supply and demand either bullish or bearish.
There are many ways to make money in financial markets, Warren Buffett found what works for him. We all must find out what works for our own situation. I personally strive for a Warren Buffett style portfolio as my core investments with Crypto and other speculations sprinkled in for flavor.