I was strongly under the impression that they always intended to implement Magitek down the line, but that it would initially be a Garlean technology.
This was how I saw it.
The city-states of Eorzea are something of an analogue to the Greek city states of old. Ithaca, Athens, Sparta etc.... The Garlean Empire is something of a "Persian Empire under Xerxes" analogue. Larger, more technologically advanced (relatively speaking) and ever a looming shadow over the lives and livelihoods of those individuals living in the main city states.
I see the Magitek stuff as "pandering" just as much as I see Chocobos and Moogles as "pandering." Which is to say, it's something that's uniquely Final Fantasy that gives the game distinction compared to other games.
TOR has the "hyper advanced yet not really" sort of tech thing going for them.
WoW has the "super dangerous but crazily awesome" Gobby tech and the "unnecessarily complicated but still sometimes useful" Gnome tech.
FF has the "let's merge magic and machine and conquer the world because f*ck yeah!" thing going on.
Yes, it's an echo of FF6, but the magitek and what it meant/symbolized is so strong and deep that really, I'm sad it took this long to revisit it. The themes practically write the story for us; the people of Grid, Ul and LL generally live in harmony with the world around them. They shape it, but they're also shaped by it, so there is symbiosis. This is best seen from 1.0 with the Gridanians and their elementals in the Twelveswood. The Conjurer's of Gridania, specifically the Hearer's, do what they can to assist the elementals and ensure harmony is maintained for all things in the forest.
Ul'dah and LL, while not as clear-cut (hah!) as the forest folk, still have a theme of "we live in this part of the world, and it's a part of us as much as we are a part of it" that underlies everything they do. It's not as obvious as it is with Grid, but it's clear the people's of Ul and LL respect the land and seek to sustain it as much as it sustains them.
But then you have the Garlean Empire. They don't "coexist" with anything. They take the primal forces of nature and manipulate them into tools of power to be used on their enemies. There is no symbiosis, no equal partnership. The empire takes and takes because ***** everything else, especially nature and the natural way of things. The only *true* way for the empire is the Empire way.
And really...it makes sense. Pretty much every single FF has had themes of respecting the world you live in, in some form or another. From the very obvious "Please not to be ******** with the primal forces of life thank you" found in FF1, to the world destruction in 6, to the juxtaposition of Firion and co. compared to Mateus (backwater freedom fighters, fighting for their freedom and the simple life, against the might of a seemingly unstoppable Emperor and his military machine)....well, let's just say this; to call SE out on "re-hashing" something or "nostalgia" at this point in time is to admit that one is quite possibly the latest arrival to the party.