Sizzers:Well, this may sound naieve but to my logic as long as it's solid, stable, and sturdy, that's all that's required. Sure, if your speakers are parked right next to the rack then I can appreciate there probably are some vibration issues, but otherwise?
What about speakers stands filled right up or half filled or not filled at all. Some heavy, some not so. Some made of steel, some made of wood. All offer a different sound. No different with your rack. Granted, a lot of people won't notice a difference in that they are happy with a decent sound and are not curious at being able to improve it with accessories. At the end of the day, surely, surely people are not all stupid to just buy because they are told to? What other industry hoodwinks people into getting punters to part their cash when there is no difference in the products they sell? Ok, apart from mineral water...