Turn that one on its head
Since quantum computers capable of beginning to attack hash algorithms like SHA-256 don't exist yet, why limit the potential to attack by quantum computers with today's restrictions?
The real question is: what qubit coherence duration is required to solve the problem? As I understand it, at the moment the coherence duration is of the order of milliseconds. What was assumed by the people offering their opinion in this article? If the coherence duration was increased to 1 second, would that do it? 10 seconds?
It seems to me, and I may be wrong, the claim that SHA-256 is quantum attack proof is based on assumptions that may be irrelevant tomorrow. One group in Australia is working on room temperature qubits based on topological properties of quantum states not physical properties like spin because the topological properties are more stable. If this, or other, research comes to fruition, doesn't that make the limitations asserted in the article irrelevant?