It was more of an opportunity initially. Bezos saw a chance to purchase extremely discounted systems. He had the foresight to move redundancy from a single host to clusters and then eventually data center level redundancy. This decision reshaped how services were implemented and scaled. Specialized devices returned because they offer a better value or in some cases enabled products that were never possible before. At the end of the day a lot of decisions are based around cost. Can you do it with a toaster or an oven cheaper? Can we cut all of our food into pieces and cook it in a Beowulf cluster of toasters? I think you get the idea.