It's not even a matter of "thought processes." It looks like wood...because it looks like wood. More precisely, examined in HD most of the TOS sets either have visible wood grain or are finished in the kind of matte interior wall paints that are hard to mistake for anything else and which betray all kinds of imperfections and seams in the material surface.
I'm guessing that some people don't see this because they choose not to, just as they choose to imagine some possible "control interface" logic to backlit plastic cubes placed in arcs and crosses that are duplicated from "station" to "station" and set to set.
The essential design and visual appeal of Jefferies' bridge has in fact continued to be the template for every "Starfleet bridge" up to and including the bridge of the JJPrise, and that's what reveals the guy's design genius - his reported complaint that, for example, the control center of the Enterprise D was a conversion of his military operations center into a hotel lounge really missed the point. We've still got the big window/TV up front, the navigator and weapons guy in front of where the captain sits in the middle of the circle, an elevator or two or three and all the other stations arranged in arcs of however many degrees around them, all in contrasting colors and all installed on several levels to make things interesting for the camera - and that's always the same.