This is essentially the "it will become so valuable, no one will want it anymore" argument.

There are uses of Bitcoin that are complementary to traditional currencies, and can survive both volatility and a large level of hoarding.

One example: an enabler of quick, distant, irreversible transfer under software mediation. That is, you get the transactional Bitcoin you need from a trusted source, then engage in a transaction with a distant/less-trusted source in a matter of minutes. Neither the overall level nor volatility of Bitcoin's pricing level matters much in such a scenario, but it still enables new kinds of transactions.

Also, for a post that includes 15 footnotes, one whopper of a claim goes without support: "Bitcoin is not meant to be an investment it’s meant to be a currency."

Sweeping claims about what Bitcoin or currencies are "meant to be" need more support and careful definition. Maybe, because Bitcoin is something new that's only made possible by computers, networks, and cryptography, it doesn't exactly fit into the classic categories and purposes.