AH (Amazon Handmade) underestimated the thinner margins that indie and handmade artists must work with, in order to compete with similar looking, mass produced product. And when selling fees eventually go to 20% on AH, it will be an even tougher pill to swallow.
Indie artists must swallow much their own labor costs in order to be competitive with the mass produced. If cost of materials for an item is $50, and the item is marked at $100 for sale, that is a $50 profit. An AH selling fee of 20 % on that item would be $20. That means the indie artists would be paying 40% of their profits in AH selling fees.
Add additional monthly fee of $40 feels like adding insult to injury. Consequently, many indie artists must balk at such high commissions.