I'll gladly solve that mystery for you.
1: Crafting ascendant saddles - they require way over 60 slots of materials. Pretty necessary.
2: Crafting at 12x speed instead of wasting time waiting for it at the smithy or fabricator. Saves a lot of time if you add it all up.
3: Crafting proper gear without non-stop having to fill up/remove the correct amount of items in a fabricator/smithy. Let's, for instance, take Mastercraft - or even journeyman - hazard gear. The mats to craft 1 mc shirt almost take up all slots of a fabricator. In a replicator you can put enough stuff to make a full set without constantly having to calculate how much gasballs, blue gems, crystal, organic polymer, etc. you need. On top of that, I have to empty the fabricator of other stuff before I can even start crafting. Big gain of time and effort if you can just dump it all in a replicator.
Only for stuff like this I need it. I don't care about tek stuff, I have a full tek base on single player and 90% of it I really don't care about. On pve you don't really need tek gear anyway.
On top of that, and this is what ticks me off a bit about this whole forced server transfer situation, Wildcard currently offers ZERO assistance when your character gets lost in a transfer. I'm a solo player so there's the small but real risk of losing everything I have every time I transfer. In a tribe you can re-join and start from level 1 if need be. Me, I would be screwed. Even if WC could help, it takes them weeks to respond to tickets so all my dinos would be gone and all my structures expired.
I'm very established after 6 months and I really don't feel like scooping up a new player that I don't know and give him admin rights over all of my stuff just to have backup when something goes wrong with a server transfer. That's insane. I've seen enough crap happen on my server to not even contemplate doing something stupid like that. At least wildcard should provide some proper assistance if they can't prevent characters from getting lost. Or just let players log on to different servers with the same character in the game menu instead of all this glitchy obelisk transfer crap. I'd be at the island unlocking that replicator right now instead of ranting about it here...