We never heard the term "warp core" during TOS. So the term wouldn't apply to the "gizmo" in the TOS engine room.
So... it's okay for TOS to give us a large open area with pipes (or conduits, whatever term you prefer) and tanks and gizmos and machines all of unspecified purpose, but it's NOT okay for STXI to achieve the same result filming in a beer brewery.
And how would a warp core be a "tank" anyway.
The warp cores were inside the large tanks/vats/gizmos in STXI. You know, kinda like the tank (or gizmo or whatever) housed the Dilithium crystals in "Elaan of Troyius"
Whoops, my bad. The pipe itself was labelled "Inert Reactant"
http://languagelog.ldc.upenn.edu/nll/?p=1435
The pipe Scotty was in was unique among all the ones in engineering, so assuming they all contain water or other liquids...
I see a corridor, packed entirely with pipes, none of which have any specified functions. I wonder what an open plan version of that section might resemble...
Scotty specifically refers to it as a "tunnel." When did we see any Enterprise corridors with conduits that needed stepping over, or ducked under?
Err... in STV?
In "In a Mirror, Darkly" we saw some similar pipe-filled engineering corridors/tubes/tunnels/whatever on the USS Defiant.
Splitting hairs over "corridor", "tunnel" and "tube" is beside the point. Ditto "tank", "pipe", "conduit", "unspecified gizmo"
It'd still look like STXI's engineering if the section was open-plan (especially if the diagrams on the walls are describing the layout of the pipes!) - or, at the very least, a brewery-like mishmash of pipes (or pipe-like conduit things) and tanks (or machinery of unspecified purpose) is as good an extrapolation as any.