Not punished, just asked that they collect sales tax instead of relying on customers to pay use tax.
To me, the implicit 10% discount to customer seems like major incentive for Amazon to not to do this rather than the technical difficulty of the issue.
I understand a startup having difficulty spending resources doing this, but not many startups have affiliates, Also, we should be worried that Amazon will cause states to make laws which will ultimately harm startups.
Complexity is a flimsy excuse for a giant like Amazon.