Imagine you have just spent eight years and many million dollars developing a library of code centered around the Cell architecture. Would you be very happy to hear you need to throw it away?
Imagine you have spent eight years hiring people, and your focus has been to include people who deeply understand the "supercomputer on a chip" design that Cell offered, which is most powerful when developers focus on the chip as a master processor with collection of slave processors, and now find that all those employees must go back to the x86 model. Would you be happy to hear that those employees will no longer be necessary?
The parallel architecture is a little more tricky to develop for, but considering all the supercomputers built out of old PS3s it should make you think. Building parallel algorithms where the work is partitioned across processors takes a lot more of the science aspect of programming, but the result is that you are trading serial time for parallel time and can potentially do significantly more work in the same wall-clock time.
Why would you throw away such a library? There is still good money to be made from PS3 ports of new games, just like there was of PS2/Wii ports of 360/PS3 games.
If I had a large number of employees who understand how to write PS3 games very well, the transition to x86 is not a catastrophe. The primary change that occurred with the PS3 was it forced people without multicore processing experience to learn it. The new processors are not going back to a single-core model, so the primary skills that those PS3 developers learned are still relevant.
If I were smart, I wouldn't get rid of the existing engineers at such a company. I would spend some extra time and money to get them up to speed on x86-64, just like that spent to get them experienced on the PS3. Also, after 8 years of working together, these people will have become a well-oiled machine of teamwork, and that is just as important as their technical abilities.
If the hypothetical library is written entirely in assembly, then yes, I would be bummed (for various other reasons as well - why is it entirely assembly in the first place?!). But if the majority of the library was written in C or C++ with some small sections in assembly, then I would not be bummed.