I think they should be responsible for accurate listings, swift refunds, taking down misleading products, and banning repeat offenders. I somehow think making Amazon "responsible for what they sell" goes far beyond that in ways that are not reasonable. Only those that make products should be responsible for them.

Well they don't ban repeat offenders. Trying to directly regulate the banning of repeat offenders seems more difficult and less fruitful than giving the store fallback responsibility for the warranty.

Australia gives the store primary responsibility and it seems to work well for them.