If you are unhappy with this trend then dig up Sam Walton and yell at him.

Walton once said that the biggest gamble he ever took was to build a giant warehouse/distribution center. His Nerds told him that he was being eaten up with inventory costs and even worse the cost of moving the inventory. So they streamlined the system and one of the things to go was the placing of some of the toys in the girls and boys sections. If a toy is hot enough the parents will find it if it is just in the toy section.

The first year the savings were in the millions.

There is still some of this boy/girl inventory at WalMart stores but everyone in the industry could see that doing away with some of it was a money saver. Target is just taking it to the next level and will save a few million a year by not juggling shelf space. Now there is no need to figure out what toy goes where. It goes in the toy section and the inventory costs are lower because a department is not costing as much to run.

Clothing is still going to be determined by sex since there are two types of human bodies and clothes need to be made that fit them. The fashion industry would need to change to do away with size norms and I don't see any savings for them if they do so.

Follow the money.