As a fellow altoholic, I disagree.

There is no lore reason to have an alt since the lore allows us to learn every job on the same character.

The desire to create a new character with a new backstory is great but what's the point of having the character if you're not playing it? If you just want to write stories, that doesn't require a character. If you are playing the character, then you can play it through the content that drops the items you want that character to have for use.

If you're just using the alt to get access to additional housing, then the alt doesn't need anything beyond what's needed for purchase requirements.

If you can't justify going to the effort to get the items on the alt, how do you justify going to the effort to get them on your main?

An alt does not need to have everything you have on your main. Players don't use most of the stuff they collect. What you do plan to use on the alt can probably be easily farmed by the alt in most cases.

The Armoire is primarily for the seasonal event gear, though they're about to add the ability to store the gear purchased from the cash shop there as well. I doubt they will ever turn it into shared account storage.

Lacking shared account storage, how would you even get account bound items to your alt? You cannot friend them to mail the items. They cannot be placed in a Company Chest where someone from another account could access them.

You've also never seen the recurring threads posted in the forums about a lack of inventory space. You may not be experiencing the problem yet but eventually you will.