Lots of local college graduates means that local companies find plenty of job-seeking graduates to fill their recruiting needs and they like that. Its means lower cost for them, both in search and relocation costs, and likely gets you workers who are less likely to move away over the long run. Lots of local employers have gotten out of the habit, not that they were ever in that habit, of recruiting for workers nationally the way their competitiors in lots of other regions need to. What that means however is that we don't attract as many people moving into the region as would be typical elsewhere.
If anything, Pittsburgh is well set up to move skilled workers around the country. A recent musing from AntiRust describes the established pathways for excess labor capacity to follow:
I ended up in Baltimore. Because my older sister lived there. Know why? Because an even older sister had gotten a job there. That's right. A job. With Westinghouse. She was an electrical engineer. I don't remember comfort or any of that being part of her consideration. It was the late 80s. That's where there was a job. So she took it. Period. And my other sister followed a few years later. As did I.
There's the Catch-22: Pittsburgh can't attract the Creative Class until they capture the Creative Class' older sister. That starts with local companies hiring outsiders, which for cost reasons and the presence of abundant skilled labor, they are unlikely to do.
I'd love to move to Pittsburgh. But I'm at a distinct disadvantage when competing against locals for a job opportunity. If there was a brain drain problem, I could easily find employment and relocate.
What does marketing Pittsburgh have to do with it?