In either case, you've still provided no good argument as to why I or anyone else shouldn't just buy an inexpensive device using another manufacturer's chip.
That is certainly a valid option, but it's never-ending. Switch to the next "hot" manufacturer, they start getting counterfeited, they implement protections, stop working with knockoff products, then you move to the next. It's the approach that pickle mentioned earlier, never spec devices that are being counterfeited in your designs (or as an end-user, never purchase devices that contain chips that are being counterfeited.
It's a valid approach for design and for end-user purchasing, but it's a moving target that you have to keep tabs on, and what do you do when you develop a product, then 6 months later one of the critical parts in it starts being counterfeited? Redesign the board to move to a new one, or tighten up your distribution chain so you're not affected? If it's the latter, then what's the point in that approach in the first place? I prefer to simply buy products that I know work, from reliable distributors, and not worry about it.
Users who simply want to scrape the bottom of the barrel in price should probably move to another manufacturer, and then another, and then another, and so on...
edit: typo