Core to the problem with money as we know it, is the conflation of assets and credit instruments. They are quite different things and throwing them all into the same box causes some strange problems.
@seneca nailed it in his first post above. Deflation is the enemy of debt, which makes it a very dangerous foe indeed to a monetary system built upon it.
Stuff getting cheaper through progress is benign though… Maybe even desirable. Computers are the obvious case study and people buy technology regardless of imminent obsolescence.
Personally, I think there is a place for assets and credit instruments. However, the latter must always have risk balanced against the former. To disregard or ignore that risk is a recipe for disaster in the long run.