I came across today two interesting articles that ask a similar question.
Should the money itself generate any return?
I don’t claim to understand the explanation given in this article, but I think it is worth reading. In the nutshell, it comes down to this assumption in economics: investors should be rewarded monetarily for taking financial risk. And
“money”, of course, is short duration or zero duration financial assets and always bears some level of risk (credit risk, reinvestment risk, inflation risk, etc).
Money may be modelled as a long-term government zero coupon bond with no reinvestment risk and no default risk. In reality, there is always default risk. Just think of Grexit saga or the US debt ceiling crisis in 2011.