Here's a thing..
Whatcha gonna do with a fleet carrier? Oh for sure, load it up with your fleet... And then what?
Let's be honest, unless it's easily jumped and doesn't take a week to grind the jump material, and it jumps a fair distance, it's actually pretty useless.
Yes, I'll but one, but only to say I have one.. I really have no need for one. I have every tricked out ship there is, can jump great distances, can mine the backside of an asteroid in seconds, and still, a fleet carrier is just another model on the shelf.
We really need to wait and see what exactly a carrier can do for our game, my game, your game.