lol why would crafters need a chocobo anyways? derp.
Headstrong adventurers that headhunt raptors all day to bring you back some items have more use for chocobos.
To add to this, crafters are considerably specialized in more local work, not having to bear the wilds to get what they need. their profession is their only work. To join a grand company is enlisting into a military. Put a weapon in your hand, not a hammer.
It makes all the sense to me. If you want a chocobo, rank a battle class to 25, should only take a few hours.