That's the whole point of free markets and competition. The point isn't that they're good for companies, it's that they are good for consumers.
I know! Those independent bookstores should just move to Luxembourg so they can compete with Amazon.
If that is the true justification for the new law, it is at best "pre-crime" enforcement - protecting Amazon from themselves, from getting into a situation where them might risk committing predatory pricing and monopolistic practices.
More realistically, follow the money and apply basic public choice theory. It's not like the economic history of the world hasn't seen this pattern a few hundred times before.