The fallacy of mal-investment is that the cause of the event is theft and not any investment at all whether it is esteemed as good or bad.
First, we identify the problem. What formerly were receipts for money then naturally began to be used as currency which acted like money. The banking system was then usurped by powerful men and sk**ful demagoguery into a monopoly of the government. What had evolved as the natural course of the business of banking was outlawed. The receipts were no longer permitted to be exchanged for money. The money itself which naturally arose was either species of commodity produced as gold, silver, and copper units. These units were also outlawed and no longer used. In the stead of specie and receipts for the metals, the monopoly commands that citizens use the paper or digital blips that the government falsely declares is money. Since we know per Aristotle's identification that money was invented as the means to equalize the value of disproportionate productive work, then the purpose of the monopoly must be to not have to perform any productive work in order to introduce new currency into the existing pool of currency. Since this new currency does not represent productive work then it is not introduced as money, but as a matter of fact it is the imitation of money. If it is the imitation of money, then it is counterfeit. This counterfeit is then exchanged into the economy of productive work as the means to extract value without having to exchange value. The use of counterfeit is not the spending of value. It is the theft of value.
Secondly, we therefore ask a question. If the introduction of new currency into the economy of productive work is the cause for values, the resources of goods and services, to be removed from their natural place and replaced to somewhere else, then how can this theft be any investment at all?
Thirdly, we illustrate. You go to work in the morning. Your neighbors go to work too and their neighbors' neighbors as well. While your entire neighborhood is away, a sophisticated group of neighborhood dismantlers come and take all that they can and rebuild a new neighborhood miles away with the value they took from your neighborhood. This new neighborhood is already accounted for and sold to very happy inhabitants. You and your neighbors return from your hard day's day to nothing. What just happened? Theft or investment?
Lastly, we conclude. The terms "money printing," "fiat money," "fictitious money," "unbacked money," "easy money," "monetary expansion," "monetary policy," "fractional reserve banking," and so on, are contradiction in terms and therefore false. The new currency introduced into the existing pool of currency is not money no matter what adjective is attached to it. The purpose of its introduction is so that those who do not produce anything of value which meets a voluntary demand can exchange this new currency for the things of value that others do produce. It is an exchange of no value for value. This "spending" of no value for value is theft, not investment. What the thieves then do with their spoils is not the event. The theft is the event.
*The official opinion of the term Mal-investment can be found here: http://wiki.mises.org/wiki/Malinvestment