Is there a reason why you can't use the ferry until you get an airship pass?

I admit, this isn't the most pressing thing to focus on for the dev team, I expect. But it does strike me as weird.

Here's why I'm irked: I like having alternative characters and I like playing them and leveling them up and whatnot. I'm also sort of a completionist, so I like getting achievements and gear for em when I can and I have time to kill.

So the Halloween event rolls around, and since it requires me to go to all the city-states, I'll need to run them from town to town. Okay, no problem, I'll just go to the ferry and... oh wait, I can't, so I suppose I'm locked out of doing the event on alts unless I try to blitz em all to 15.

But why is it set up this way? It strikes me as odd that if you have characters starting in Limsa, you are basically locked to Limsa, unlike if you start in Grid and Ul'dah, you get access to a full four regions to explore.