Where this came from, I'll never know. If, in fact, Penn State is a top notch academic University, it should be apparent to the grads that Pitt is just as good, academically. There is a difference in lifestyle. Pitt is in the heart of one of America's great cities. Penn State is in the heart of one of America's great states.
Personal preference is the difference between the two more than anything else.
Oh, and attitude is perhaps the largest difference between students at these two institutions. Penn State fans get great joy out of pointing out that Pitt can't fill up their stadium. There are reasons why, but never will a good Penn State fan allow facts to interfere with their opinions. For Pitt fans, there is some distress in that many of the best high school players from Pittsburgh attend Penn State. It isn't a point of anger, mind you.