It's probably not the reason, but it's worth noting that the author is using Amazon affiliate links in violation of Amazon and FTC rules because they're not disclosing the fact that they profit from purchases through their links.
Per Amazon:
>Anytime you share an affiliate link, it's important to disclose that to your audience... you must (1) include a legally compliant disclosure with your links and (2) identify yourself on your Site as an Amazon Associate with the language required by the Operating Agreement.
https://affiliate-program.amazon.com/help/node/topic/GHQNZAU...
Per FTC:
>As for where to place a disclosure, the guiding principle is that it has to be clear and conspicuous... Consumers should be able to notice the disclosure easily. They shouldn’t have to hunt for it.
https://www.ftc.gov/business-guidance/resources/ftcs-endorse...