Pittsburgh really is a lot better than it was, say, 20 years ago. It's hard to believe, but it's become a bit of an artistic and cultural Mecca.
Cleveland, on the other hand, is one of only about a half dozen US cities with a rape rate higher than Toronto (out of the 50 largest US cities). Cincinnatti and Columbus are high, too. There must be something about Ohio.
Just of the top of my head, I would rather live in any of these cities than Pittsburgh or Cleveland: (not listed in any order)
Boston
Miami
San Francisco
Seattle
San Diego
New York
Chicago
I'm sure I can think for a bit and come up with many more.
It really does call the study into question. It's why I don't like these "best city/best country" studies. I don't think they are very valid. And they might not be measuring what I would want measured.