That is not a good decision. But let it be on his own head.

Bitcoin has nothing to fear from quantum computing. It is not some legacy system that cannot be updated. To the contrary, it is updated regularly. Why would he think that we would not also implement quantum proofing when the time comes? It's not like we do not know the limitations of current quantum computers. We can easily guess what future quantum computers will be capable of. There are always ways to proof the system.