Hi Bill,
On the one hand you certainly have to admire the talent of Robert Lee using very low cost passive parts and getting such truly high quality sound. A quite talented builder with excellent design and execution of the Cresendo.
However I do see your point and agree that the wise selection and placement of high quality resistors and capacitors will yield more from this fine speaker. Those passive parts do sonically matter. No harm in making something "very" good even better with thoughtful part upgrades.
Charles