There are 12.5% more memory cells for a given module size, which equals more targets to possibly be flipped by cosmic rays. It’s not crazy to think that modules

There are 12.5% more memory cells for a given module size, which equals more targets to possibly be flipped by cosmic rays. It’s not crazy to think that modules of equivalent quality (same brand, same chip part numbers) would experience a greater incidence of that kind of single bit flip (which would be corrected on the ECC modules). If a manufacturer were shipping chips prone to bit flipping because of slightly radioactive packaging, as happened at times in the past, you might see something similar. But you’ve got it backwards about the incentives. A manufacturer has less incentive to deliberately ship a defective part in the case of ECC modules. If the modules consistently log ECC errors, they can easily be identified and returned under warranty to the manufacturer. A consumer is much less likely to identify an intermittent problem with a non-ECC part.