I believe you are right to blame the wood, The reason the hand build custom bass luthiers hand pick their timber and ensure it is the best seasoned material is because they understand that this is the fundamental building block of the bass tone just as a tuning fork resonates loudly when placed on a solid surface. The body and neck woods are key to how well the bass will resonate. I also believe that playing the instrument - any instrument wood or brass will help align the molecular structure withing the material just like stroking a nail with a magnet to align its molecules to form a north and south pole. Instruments get better with age and that means exposing them to the range of frequencies they need to propagate a good tone. Every mass production bass line will have good basses and lemons, which is why you should always try as many as possible, you may want a salmon pink bass but the blue or black one in the shop may be the better bass.