If you have 0.01% failure rate and sell a million devices, that’s a hundred expected failures. Some of these buyers will want to blame someone, so they’ll go on

If you have 0.01% failure rate and sell a million devices, that’s a hundred expected failures. Some of these buyers will want to blame someone, so they’ll go on Amazon telling everyone that their study with a sample size of one shows how incompetent YourDriveBrand has become, and that they should never buy from them again. The average rating is probable a better indicator here.