And how do you know we aren't also going to use a spell or ability to tame a gobbue? Or get a gobbue egg and "tame" him? Or you know, any other possible in game explaination they are surely going to give us about how / why we are able to mount them?
We've had people taming Dragons ,Sea Serpents, or literally every single regular monster in the game in this damn series, but suddenly mounting an enemy "breaks your immersion" and "has nothing to do with Final Fantasy" as some others are claiming?
Just admit it, the "breaks my immension" argument can just as easily be changed to "I don't like it". Go ahead, just be honest and say you don't like it, it's perfectly fine.