I know product support very well- agreedI don't have an exact timeline, but very roughly the first rumbles there might be some kind of problem with these CPUs started popping up in February. Around April it got loud enough that Intel started doing something about it and the first step was to curtail some of the more excessive optimisations mobo manufacturer's set. It should be noted that in the past, and it might still be the case, system builders were given the freedom to freely adjust power limit alone. This was not considered overclocking and was allowed. There are many other things that can be tweaked, and I don't know which ones would or wouldn't be considered out of spec by Intel. As time moved on Intel found an eTVB bug, which was not the cause but still they fixed it. Later again they found the voltage problem, and the latest one was which part got worn out first by that excessive voltage, along with yet more voltage optimisations.
So back to the question if mobos were to blame, kinda but not. Without the latest fixes, it seems like the CPUs would still degrade at a higher than expected rate over time, although maybe it would have been slowed down for some people.
If you've ever had to work in product support, it really isn't as simple as some think that you report a problem, someone looks at it and fixes it quickly. It could happen for something simple, but this was far from simple. It is about worst case since it varies slowly over time. Problems that are easy to repeat on demand are much faster to find.
Thanks for this. True re complex on this one to me at least.