before we get into a senseless argument, you should realize that I respect your opinion, but I see different logic and am merely stating that logic:
in my own opinion, the wood of a guitar affects tone because although the pickups are picking up that signal, the wood is what's being the soundboard for the strings vibrations and that different woods react differently under different situations, while in a speaker cabinet the following applies:
1) the speaker is what is doing the vibrating, and therefore the size, cone material and magnet matters.
That's sort of like saying; "The strings are what's doing the vibrating, and therefore it's the pickup magnets and windings that matters". Most would agree that, while this is true, the wood used in an electric guitar plays a major role in tone as well. Put your hand on the speaker cabinet while the speaker is vibrating. Now try to tell me that the cabinet is not vibrating also. Every object that vibrates, does so at it's own resonant frequency.
2) the wood is usually a ply, or particle board any ways, which offer little in the way of natural vibration.
The vintage Fender cabinets are made of pine board, which is not ply, nor is it particle board. It's board lumber. Yes, many cabinets are made of birch ply, but that's still a far cry from particle board which is a heterogeneous sawdust that's held together with a lot of glue.
3) although the size of the speaker cabinet does matter because of the resonance frequencie (larger cabs, lower resonance frequencie, smaller cab higher frequencie), the species of wood is usually chipped to hell and glued together, which in my opinion, offers little in the way of tone.
While the size of a speaker cabinet does matter if one is trying to achieve the optimum resonant frenquencies, but that's only true with closed back cabinets that are sealed and air tight. Besides, that is only true if one is trying to accurately reproduce already established frequencies, as in recorded music. Creating music with an instrument is another matter altogether. You are trying to create a particular tone and everything in the signal chain contributes to this, including the speaker cabinet construction. Again, the pine cabinets are not chipped and glued together.