And yes, the error correction routines are themselves fault-tolerant. By the time cold fusion was 5 years old, it was already completely and thoroughly discredited. Shor's algorithm is 6 years old, and quantum error correction is 5. Quantum computation, as a field, is still growing rapidly. In computer theory we rarely can prove something is impossible.
Quantum computation challenges it.
A fundamental failure of quantum computation would be every bit as disturbing to physics as its success would be to theoretical computer science, probably more so. Quantum mechanics, after all, is twice as old.