And I'm not merely careful to filter stuff. Amazon is no longer my go-to in general. I do buy stuff from them sometimes, but they're not the first place I check for most things.
A less savvy buyer probably won't even do that. If they get burned too badly on an Amazon purchase, they'll just abandon Amazon, not learn which checkboxes mean "hide the scams."
If I have to do careful homework on the seller for any Amazon purchase anyway, it's just as easy to find a more niche e-commerce site, or use a dedicated marketplace like eBay or Craigslist.
I still use Amazon's dedicated product sites like Zappos or Diapers.com. I feel much confident I'm going to get what I ordered there than on Amazon.com.
To be clear, there are some specific purchases I would not make over Amazon. Amazon's clothing section is a complete joke, for example. I also like B&H, and use them when buying high end equipment.
There isn't any general-purpose store I prioritize over Amazon, but usually I know which stores sell the things I want. For example, Home Depot often has better deals with less search hassle than Amazon for hardware stuff.
The fact that Amazon's search is essentially unusable is a longstanding criticism.
My go-to is now froogle.com (Google's product advert index). It used to be Amazon, but they have way too many issues now.
Shame because I previously bought dozens of books completely hassle-free
Any shopper who's been burned will still use Amazon in the way you are, just being careful to filter by Prime and/or Fulfilled by Amazon. So the damage to the core brand is minimal even for rare cases like OP, who even ends his article with "even if it’s through an online retailer as trustworthy as Amazon." Despite this experience, he'll still buy his memory cards and Whole Foods groceries over Amazon Prime.