People here are unfriendly, lazy, and overly excited about football... because football is pretty the only thing the city has.
Shitty public transportation (expensive, rude drivers, full of load idiots). The city isn't progressive at all, and most of the things that could make the city nice either don't get started, don't get finished, or get ruined by the shitheads that live here.
Most of the people that live in pittsburgh are all college douche bags, that go to school during the weekend, then terrorize the city (mostly south side) on the weekends, by being too loud, littering, and destroying anything in their path.
And this is all coming from someone raised here.
If you are looking to visit a city full of friendly people, this is not the place.
To most people living here, there is no world outside of pittsburgh.
Also, there is so much water. Three rivers meet at an area Pittsburghers have come to call The Point, and there's a cool fountain and picnic area there. Pittsburgh is also notorious for flooding.
Finally, Pittsburgh's weather is off-the-wall. It's May as I'm writing this, and we had snow two weeks ago, warm-ish rain last week, and this week we're expecting it to be cold. Still.