I do not dispute the claim about the existence of a quantum computer which surpasses its classical brethren. Scott is correct.
I do disagree that it is exponentially more difficult to add a qubit. Coherence times are something to optimize, and densely packing qubits is also difficult with coherence times, but the notion of adding a qubit to a system doesn't come with an inherent exponential difficulty.
Regarding whether it is useful or not to learn quantum computing for your profession, if it's true that systems can be built that grow with exponential power, then they'll be relevant faster than one might think.
I do disagree that it is exponentially more difficult to add a qubit. Coherence times are something to optimize, and densely packing qubits is also difficult with coherence times, but the notion of adding a qubit to a system doesn't come with an inherent exponential difficulty.
Regarding whether it is useful or not to learn quantum computing for your profession, if it's true that systems can be built that grow with exponential power, then they'll be relevant faster than one might think.