I think more than anything else it was the volatility of chipset/sockets. You had 940, which required registered, 754 which was EOLed almost before it began, and then 939 which ended up being EOLed too quickly. I mean, great that it had a performance crown, but that was just horrible execution and probably contributes to the validation issue.
.
AMD's issue they ran into when they had better products in the past was not validation complexity due to frequent socket transitions. Validation issue due to socket transition implies that the idiots designing the system did not even bother to check & make sure CPU & MB are same sockets. This is not validation phase, it's critical fail at design phase. Validation processes vary depending on intended use and requirement of finalized product but a typical validation focuses lot on potential undocumented issues rather than well-documented problems such as socket mismatch in CPU/MB components.
Rather, the issue discussed at hand in the article was that customers, large or small, wanted to deal with platform solution provider versus CPU supplier + MB supplier + sometimes graphics chip supplier, and this is not only a matter of convenience but an advantage to the customer (consistency in support, technology, and services) which cannot be easily dismissed.
Many people think that AMD purchased ATi because of the graphics business/gpgpu and as such will eventually birth Fusion technology.
This is true to an extent, but the underlying motivation for ATi purchase was for AMD to mimic Intel to become a platform solution provider because as AMD sales force were finding out at the time, many customers won't even let them in the door even though they had the advantage of having a better regarded CPU product at the time.
As for socket migration management, I personally much prefer AMD's socket to socket (CPU/MB) compatibility with relative simplicity (BIOS update notwithstanding) than Intel's where some existing socket MB may be compatible with new CPU of same socket, sometimes with BIOS update only, sometimes BIOS update only ensures partial list of new CPU compatibility and the kicker... same socket MB which are just completely incompatible with new CPUs...
This was the story with socket 775 and C2D CPUs I believe...