He's essentially using the argument that since bitcoin fell by this much within the bear market, it must continue into the future. He's not backing it up with any analysis, it's purely opinion and speculation.

We all know that he's wrong - bitcoin can't be worth zero as long as there is a demand for using the network, and there will always be demand for it.

Does he not understand that bitcoin is just currently in a bear market, and due to the volatile nature of bitcoin, it essentially means that bitcoin has always historically corrected around 70-80% down from its peak before recovering?

The article sums it up pretty nicely. To us, these sorts of articles obviously don't carry any weight given we know what's going on with the market. The mainstream may be misled into believing it, though.