I've lived in the midwest and the southwest. The southwest is a much, much nicer place to ride, that's for sure.
The problem is that it's hard to be really good at climbing if there aren't any climbs around. I was born and raised in a flat area, but I have the body type of a climber. As soon as I got the chance to regularly do some climbing I became good at it, but it does take a while. I've only been back in the midwest since December and I've been riding just as much, but I know if I were to fly out tomorrow and tackle a big climb that I wouldn't be near where I was when I left. Practice makes perfect, right?
So there are plenty of people everywhere who have the potential to be good climbers, but they'll never realize that potential.