I will just say to Karel that if the device fails when not doing a critical test or being used for something you actually needed to do it is perhaps acceptable to force the innocent end user to return their device for repair. No very comforting if you actually were planning to use it during the days, weeks or months required to resolve the issue.
You would suggest that this experience will encourage people to choose vendors who are more careful in controlling their supply chain. Valid point. This would reduce the risk of problems of this nature, although it is impossible to eliminate them totally. But choosing avoid FTDI parts and devices incorporating them is also a valid choice, in that there is potentially less risk of negative consequences from a mistake.
Hopefully FTDI thought of this when they evaluated their response to those counterfeiting their devices. Only time will tell if their revenue is sustained or improved by their actions, or if they are financially hurt by them. I can say that if I were them I would be nervous about the outcome, and as an investor I would be cautious. The answer is not obvious to me.