In other words, his article was mocking both the people that claim bitcoin is in a bubble and the people that claim that it is not.
I think his argument is basically correct. Anyone who uses the term bubble, asserting or denying it based on valuation arguments, is probably thinking about Bitcoin incorrectly. They are assuming that there exists an objective "intrinsic" BTC value from which you can calculate a deviation. Flawed assumption.
What is a bubble? It's when the current price of an asset exceeds the present value of its future cash flows. If you can't specify those flows, as is the case for BTC, Gold, Silver, USD cash, etc. then talking about bubbles in those assets is meaningless, pro or con. You cannot establish an objective value for an asset consisting mostly of a monetary premium; that premium is entirely based on subjective demand and sentiment. Both of which can go up and down instantly due to external unpredicable factors.
The most that can be debated about Bitcoin (or gold, or USD, or any other asset mostly made up of monetary demand) is whether its future demand/supply will increase, or decrease. Increases in demand, absent similar increase in supply, will lead to increases in price, and viceversa. Adjectives like bubble, overvalued, undervalued, or anything else that implies comparison against some mythical "fair" objective valuation, are technically based on a false premise and guaranteed to lower the quality of the discourse.
The price of BTC is neither a bubble, nor a non-bubble. It's just a price. A reflection of supply and demand at any given moment. The only useful debate worth having, is whether supply and demand in the future will go down, or up.
I happen to think, based on its properties, that demand for Bitcoin will continue to increase, due to its utility and advantages over other forms of money. And that that increase, coupled with limited supply, will in turn lead to a rising price, measured in many digits in the best case scenario. No bubble analysis or defence necessary.