This is a good question. It rests on an implicit assumption that we think Amazon's behavior is anti-consumer ("bad") and Costco's is not ("good"). But perhaps

This is a good question. It rests on an implicit assumption that we think Amazon's behavior is anti-consumer ("bad") and Costco's is not ("good"). But perhaps one way to resolve this dissonance is to consider that Costco's behavior is anti-competitive too. They are a beloved brand, but that doesn't mean our emotional attachment to Kirkland products is an accurate reality-based moral stance.