The major difference here is that Amazon has major market power as an online mall.

Like with the sears example, large 'mall' like organizations do outright steal designs and stonewall the original copyright holder.

A random housebrand does not have access to Amazon's statistics, logistics or reach. Amazon is looking at stats that they hide from their providers, to choose who to copy, then out-price the original seller. (Due to inhouse logistics)

They are not even remotely the same thing.