Having both options is great. Let's face it, Anima runs out. Quickly. And adding airships that didn't have a fast travel option would have done nothing to alleviate this (contrary to popular belief) because instead of going "Well I'll just take the long airship ride, at least it's immersive yay", it'd be "Screw that airship, it takes 10 minutes to get to town. I'm gonna ask for a teleport and pay somebody to get there".
The only way adding airship travel was going to stop people from using Anima is if it offered the same speed of travel. Which is instant. Airships don't make Anima useless (as you have way less options for destination on airship travel than you do with Anima), but it does make it manageable, which was the point. But that isn't what most people complaining wanted, unfortunately. They wanted something more like "Yay we got our immersion, and you can't have convenience! Unless you have Anima that runs out with no way to restore it other than time, of course. Oh, you don't? You have to take a long time to go somewhere, we're forcing our immersion down your throat! We win, you lose!".
Now, people trying to go from say, Gridania to Limsa quickly will go, "instead of using my Anima I can pay some Gil and take the airship over to the Limsa, and get there quickly so I can do what I need to do there". And for the people who want the immersion, it's still there. It's not magically going away because other people might need to get there fast and use the instant option. And they'll probably add features that will make people want to use the long version when they have time.
Ultimately, in this case choice doesn't make it a gamebreaker. It just makes everyone happy. Well, it doesn't make the people who want to force everyone to do it their way or the highway happy.
