My understanding of the issue, when I was in Pittsburgh ('09-'13 and '15-'19) was that it was a combination of Clairton Coke Works pollution and unfavorable win

My understanding of the issue, when I was in Pittsburgh ('09-'13 and '15-'19) was that it was a combination of Clairton Coke Works pollution and unfavorable winds/weather patterns that would cause the smell to stick around. I definitely know the smell he's talking about. But it wasn't every day, maybe not even most days (anecdata, I know), and not terribly strong where I was (Squirrel Hill). Personal opinion: lots of cities have specific quality-of-life issues of varying degrees; in the Mountain View area now, I could equally complain about Superfund sites from all the early silicon industry dumping. Overall in Pittsburgh, the walkability, easy access to hikes through large parks in city limits, lack of stress about high rents, etc., probably outweighed an occasional whiff of sulfur wrt my quality of life. Everyone is of course welcome to make that tradeoff differently!