> A key problem with the complaints is that customer reviews don't† take into account the effect of commingling.
There is no problem with the complaints. Consumers ordered something, paid for it and got a bad product. They have every right to complain and shouldn't be required to "take into account" operational failures of the company they did business with.
> The expired food might have come from a different seller initially, but you were sent it because of Amazon's supply line optimisations.
How is that the consumer's problem?