if women stopped buying pocket-less pants, they would cease to be sold in that volume... or rather, the best way for the general population to resolve this would be for a volume of disgruntled women to only frequent the few suppliers of decent-pocketed pants.
money talks, and they tend to sell what people buy... especially with these low-margin, high volume items. excess inventory is a big liability.
edit: a more specific answer to your question i guess would be, "women choose the silhouette of no pockets over pockets"... its about looks
I love pockets but I’ve noticed that many pants i try on that have pockets don’t fit right. Pockets sit right around the hips for women, and can bulge depending on the design and material. I think I’ve unconsciously bought a lot of pants without pockets because of this. When I actually wear them out, they look nice with clean lines, but no pockets … and I am sad.