Kim,
My first thought was to keep the lines in the outfit flat.
I googled it and got this
Clothing lines hang better without the added bulk of usable pockets. Just seams are easier to create fitted lines. Once you add a real pocket, the lines have to adjust for extra fabric.
Designers assume (and push) that women carry purses all the time, removing the need for usable pockets.
The fitted styles of today don't allow room for usable pockets. This is an extension of #1.
Personally, I despise that I can't just run out with my wallet or ID and some cash without worrying that it will all fall out of my pant pockets. I normally carry a purse, but sometimes it would be easier not to so I carry a small cross body bag.
