However, the lack of reprocessing beyond simple plutonium exaction increased the demand for uranium ore. This lowered prices and because waste was not reprocessed early stockpiles where created, even if they where not in fact used. So, the impact would have been minimal except the lack of innovative R&D calcified the industry around this approach.
Further, there was an actual attempt to extract plutonium from civilian reactors: https://en.wikipedia.org/wiki/West_Valley_Demonstration_Proj... was really a legacy of this failure as it only produced 4,373 lb of plutonium vs https://en.wikipedia.org/wiki/Hanford_Site which produced most of the US's plutonium for nuclear weapons. Which is why I feel this is a little more nuanced than your suggesting.