I don't understand why you would call traditional assets gambling while cryptocurrencies are being called the future of investments because that doesn't make much sense. The traditional marketplaces are indeed unpredictable, but so are cryptocurrencies and this market, both markets are volatile, in fact, the traditional markets are pretty mature now and they have more trust among investors be they retail or industrial investors.
He should have called the cryptocurrency market a gamble and not the traditional market because, there are many things that is yet to be cleared in the cryptocurrency market. Investors are yet to trust that they can invest their money and it will not be lost because the market is very unpredictable. The market does not have any reason for investors to believe that it will be around for a long time, many projects have a very short lifespan and if you invest with the hopes of holding your investments for a long term, you will be at losses at the end of the investment. There are many projects getting launched and before the end of the bear market , they are no longer existing. Untill project can give investors trust in their project like Bitcoin has done for people that are investing in it, we might not be ready for the cryptocurrency market to be the preferred investment market.