There it is, right there.  Your great fallacy.  Money doesn't try to do anything.  It's an inanimate object and/or an abstract concept.  Money doesn't do anything that people who use it aren't trying to use it for, and if people wish to use it as a low risk store of value, then that is what it is for.  Any attempt to design a monetary system that deliberately tries to alter the behavior of those people to do with it what they will is doomed to failure so long as there exists an alternative that avoids those 'features'.  Since such a cryptocurrency already exists, designing an alternative to bitcoin that uses demmurage must have some other overwhelming advantage to the user to ever stand a chance to develop an economy in the first place.