My pet peeve with Amazon is a similar "nice but not quite good enough feature" : their selling of fasteners. Nuts, bolts, etc fall into a clear if quite complex N-space of sizes and features. This can be represented nicely in a web site, for example : http://www.mcmaster.com/ however even though Amazon acquired a nuts-n-bolts retailer some years ago, their site is a horrible mess for this kind of item. I'm not sure if this is because there are no humans curating the catalog, or because Bezos doesn't do his own maker projects and vehicle maintenance...