I don't buy drives on Amazon for my 9 year old's laptop because of the rampant fraud and counterfeiting, I'm shocked that they're trusted for any business use-cases by anyone moderately savvy. I'm even more shocked that the takeaway is to blame the individual seller, rather than the marketplace that makes it possible.
I buy drives on Amazon all the time. I check them all. Never had any problems.
The mistake they made was buying not from Amazon, but from "Maestro Technology" listing on Amazon. If you understand that Amazon is a marketplace and you take 10 seconds to read who you're buying from, it's not a problem.
Amazon returns are also extremely easy. I once gambled on a sketchy seller and received a bad product (not computer related). A couple clicks and it was on its way back for a refund.
The problems with inventory commingling are virtually a thing of the past. I went through the process of selling a product on Amazon and understanding their evolved inventory labeling and commingling procedures so I'm not worried. Many of the tech community are anchored to news articles from years ago, though.
If you have a highly trusted vendor who can deliver at great prices and have products in stock that show up at your door when you need them, then use that. For the rest of us, using Amazon to buy common parts isn't really the problem that it's made out to be in HN comments. I think a lot of people here only understand Amazon through the occasional article that makes it to the top of HN and they don't understand what it's really like because they've been too scared to use it for years.
If a marketplace is prone to scammers, and is unable or unwilling to get rid of and assist in the prosecution of the scammers, then it is 100% the scammers' fault.
No, "force the seller to create yet another account" doesn't count as doing anything.