Of course body wood matters. All the materials used in the construction of an instrument matter. The wood does affect the tone. Where people go astray is in thinking that each wood species has a consistent and predictable effect on tone, ie: "maple is bright sounding". It's not as literal or direct as that. The wood's properties do matter though - its density, hardness, etc have an inarguable effect on the sound of the bass. To prove this you could try taking the wood out of the equation - literally - and play a hollowbody bass. They sound different. So if the absence of wood in the body changes the tone of the bass, it stands to reason that woods of varying density are going to have varying effects on the tone too, however subtle. You could even argue quite reasonably that different species of wood have different average densities and hardness, which suggests that there may in fact be some consistency to the tonal contributions of different species. Maple may in fact sound brighter on average. You might very well think that. I couldn't possibly comment.