I will be the naysayer on this one - having grown up with 3 sisters all active hikers, they would laugh at the concept that they need a device to pee or crap in the outdoors.
- I.P. Freeley
Women have taken care of business for many thousands of years without their assistance so it can be safely assumed they aren't strictly essential. They make the process much easier, safer, more private, and potentially less messy.
I know ladies who avoid any situation or event where toilets are not available. I have traveled with some who severely limit water intake to limit their need to urinate and juggle routes and schedules to accommodate their need to urinate. This is not just a major PITA for them it is potentially dangerous.
These simple devices are not, cannot be, a complete answer but if they allow the ladies to travel more comfortably and maintain proper hydration without excessive bother or worry they are worth their price and deserve consideration.
I have been around some amazing ladies. One used to pee standing up off the back of a shrimp boat while under way, and not get a drop on the boat. That's talent. Most men can't manage that. One can assume that a lady-J wouldn't interest her because she gets along without one.
It can be pointed out that a Freshette, particularly one with a longer hose, can be handy for men. Peeing into the shallow funnel as easier while sitting than using a bottle. A longer hose allows you to keep jug on the floor. A hole in the floorboard is a good alternative to a storage container. I have located a funnel and hose on many vehicles for just that sort of situation. If I have a funnel there is no reason to not make it a unisex design.