I thought I would pop back again now that I've actually crafted an airship rather than just reading about it. Having had first hand experience, I can definatly see why the restriction was put in place because trying to craft a ship solo would be soul destroying.

It took me and two other crafters a whole evening to create our FC airship. This may not seem like much, but this is the most basic version of the ship where about a quarter of the mats could be bought from beast tribe vendors and npcs. We also spent around two million on timed gathering materials such as Darksteel nuggets.

That is just one airship down with three more to go and the material, time and effort required just getting harder from here on out. Yes you could craft an airship solo but I am sure it will end up as difficult as doing the whole relic line. Hell, I'm even going to be helping a small FC I have friends in complete their airship after how hard it was to do ours.