It makes sense, all the cryptocurrencies in the market are commodities just like bitcoin, there is a major difference between crypto and securities like bond stock, people buying stock in a corporation expects to gain profit from the company's success. Securities providing companies and government with capital and investors with the potential for returns.
When a coin was an ICO, yes it can be categorized as security, but over time it will change become a commodity.
Tarbert acknowledges “ambiguity in the market” on the status of many coins, but says that ultimately “similar digital assets should be treated similarly.” If the underlying asset, the original digital asset, hasn’t been determined to be a security and is, therefore, a commodity.