Limits to quantum computing

A new paper, Quantum Computing: Theoretical versus Practical Possibility, by G. S. Paraoanu, says:

An intense effort is being made today to build a quantum computer. Instead of presenting what has been achieved, I invoke here analogies from the history of science in an attempt to glimpse what the future might hold. Quantum computing is possible in principle - there are no known laws of Nature that prevent it - yet scaling up the few qubits demonstrated so far has proven to be exceedingly difficult. While this could be regarded merely as a technological or practical impediment, I argue that this difficulty might be a symptom of new laws of physics waiting to be discovered.

Yes, I agree with this. I think that building a quantum computer will eventually seen to be like building a perpetual motion machine. Progress is an illusion. Quantum computing is not really possible in principle, as it depends on ideas that have never been empirically demonstrated.