For me it's all about reducing the diameter of my thighs so I can be comfortable in hot weather. I get horrible chafing whenever I wear a skirt or shorts and I hate it. Any shorts I wear ride up between my legs, too, which is awful. I don't think I'll achieve it this summer, but I'd love to be able to wear shorts again. I could in college, but haven't been able to since my sophomore year.
I love wearing skirts, though, and if I didn't chafe so much whenever I walk any distance without shorts on underneath, I'd wear skirts every day in the summer.