WHY would you need an ALT for this??? Really. Tell me. You don't need to max level any skills, you don't need any skills AT ALL in fact. Making water bags requires no skill, filling water bags up FOR FREE requires no skill, carrying water bags only requires carryweight, Using water bags requires NO SKILL. You DO NOT need an alt for this.
Nice straw man arguments you've got there, but I'll play along.
Of course you don't need alts for crafting water bags, neither do you need them for filling those bags up with water. However, to craft a water bag, you need resources: one brahmin hide, and one bunch of fibers, which are not readily available in many locations.
That means you need a tent with water bags in it next to every possible respawn point, and also, preferably, every 2 squares of the world map, just in case.
This means that if you want to actually travel around the world map, and not just grid-camp gas station in New Reno 24/7, you'd need approximately 100 additional tents (or a car...) in order not to get constantly annoyed by the lack of water... if your idea got implemented, that is, which I hope is never going to happen.