You make it sound as if these trends were inauthentic. I think they were, in fact, organic outgrowths of the city's strengths. As long as Carnegie Mellon and the University of Pittsburgh are there, there will always be a strength in tech and medicine. I was a bit too young to be much of an observer of the 80s as they happened, but finance was most likely a strength due to Pittsburgh's prior status as headquarters for a significant number of Fortune 500 companies and banks: PNC, Mellon Bank, Gulf Oil, US Steel, Alcoa, HJ Heinz, Westinghouse... At the tail end of the postwar industrial boom, there must have been a good deal of money in Pittsburgh, ready to create a financial hub.
not nearly enough new-world accoutrements
Can you give examples? As others have pointed out, I think PGH does a great job of bridging the gap between a large, cosmopolitan city and a small town where you don't have to feel lost forever. Of course, as you point out, the flip side to that it is a small town--you have to very careful to avoid burning bridges because it is highly likely you may need to cross that bridge again at some point.
(Edit: fixed formatting)
As a mostly life-long 'burger (up until I was 26), I disagree. In fact, I'll claim that if you're a software engineer in Pittsburgh, then you're in a dead-end job as long as you remain in Pittsburgh.
Yes, you'll have a very nice quality of life; however, you have significantly less opportunities as a software engineer there. Aside from a few firms, Pittsburgh doesn't have an industry that provides the environment, training, challenges and opportunities of both large technology firms and a robust startup community that you see in other major tech hubs. This lowers the wages and, to be frank, lowers the quality of engineers available to hire in Pittsburgh. It makes it more difficult to move out for engineers who have spent the formative part of their career in Pittsburgh.
And that's fine. Software programming isn't the be-all end-all of human activity. It's awesome to be part of something bigger, delivering real value aside from shipping the next social-photo-sharing-app. But just because you can get software programming jobs in Pittsburgh in no way allows Pittsburgh to compare to San Francisco, Seattle, NYC, LA, Boston, Austin... It's just not the same environment and we shouldn't pretend it is.
On the other hand, given the rate that Google is growing in Pittsburgh, I suspect they'd disagree with you about available talent quality.
(On the third hand, "quality" is a fuzzy metric unless we nail down more concretely how one would evaluate it. Is someone writing thousands of lines of code per day at Facebook higher "quality" than someone writing a hundred lines of code per day on machine-learning cancer detection logic?)
That's not to say there aren't good, indigenous engineers, but, rather, that Google has a nice farm system in the local universities.
Maybe the seeds were sown in the '90s and they sprouted in the aughts? I'd have to know what was attempted in the '90s to evaluate the question; looks like I have some research to do. ;)