The point is that buying a thing off Amazon's site that turns out to be something unexpected or a scam devalues Amazon's brand, whether it's vetted by Amazon or not. Amazon make a point of not separating their vetted stuff from their third-party sellers intentionally.

If it gets to the point where it's difficult for me to find products of the quality that I want on Amazon, I'm not going to worry about whether it's Sold By Amazon or not - I'm going to find an alternative.