The real difference between corridors and turboshafts is that you can walk across
a corridor. If a set of cabins is to be provided access by corridor, the corridor goes through two rows of cabins and each has a door opening into the corridor. If the access is exclusively
by turbolift, same thing. But if you want both types of access (a definite must in emergencies), then turboshafts severely block corridors (at each cabin door!), whereas corridors don't block other corridors at all, and only block turboshafts at key junctions. You really don't want a corridor and a shaft running parallel because that blocks 50% of corridor access - but you don't want shafts crossing
corridors, either, because that truncates and terminates the corridor.
So what you do want is shafts that dodge and weave, climbing over or diving under corridors - but that sounds like a nasty thing to turbocab speed and durability, as all those tight turns must be hell on the machinery.
The alternative is vertical dodging and weaving by corridors rather than shafts, which would make a lot of sense but is prohibitively complex to do on a TV studio floor.
alternative would be to have entire decks dedicated to turboshafts, between corridor decks; there's probably plenty of random machinery that needs to go between decks in any case, enough to justify a "tween deck" just barely high enough for a horizontal turboshaft (or then just barely not
high enough, so that you have the occasional slight bump on a corridor floor and the occasional low overhang on a corridor ceiling; might look cool).
It seems like, at least on this version, the designers are assuming that turbolifts are the primary means of moving around on the ship.
Also, they are creating maximum compatibility with what we really
see happen in the episodes: our heroes walking on a short section of a curved corridor and its radial branch, which is all that exists on the set. This is how you access a random room with a long but fast lift ride and a short but slow walk; if you walked along a greater length of a curved corridor (and thus out of the set!), or took a multiple series of curves and radials, you'd be trespassing on territory better accessed by taking the lift to a closer terminal.