"Foreign Direct Investment" is to be understood as bringing in an economy productive capital, and not just purchasing power.
When an economy is seriously below full employment (of capital and labor), than a case can be made that "printing money" (i.e. creating purchasing power out of thin air) may not result in just inflation, but it may indeed bring into production input factors (labor and capital) that are currently unemployed. Compared to Foreign Direct Investment, we have the following differences:
Creating purchasing power through printing money relies on an indirect effect: you strengthen demand and expect that this will lead to increased supply, which in turn translates into higher employment/output. This may mitigated by a) increased imports rather than increased local factor employment to satisfy the demand b) institutional issues that may obstruct bringing into production the idle local factors c) imbalance in available unemployed factors - e.g. you may have too many unemployed people but not much unemployed infrastructure.
Foreign Direct Investment in almost all cases is partly translated into imports (the foreign investors bring in their funds which are then partly paid back abroad to import capital infrastructure that is not available in the local economy), but apart from that similarity it a) increases supply and local employment directly and b) by design it takes a priori into account the possible imbalance in the availability of local factors, and corrects from them, since it wants to arrive at a factor mix that will be able to produce.
In a more general perspective, we could say that by printing money, if the policy fails you will just burden the economy with inflation (which has transactional costs). But with Foreign Direct Investment, even if it fails eventually as a commercial enterprise, the local economy has nevertheless gained, even as a one-off, the part of the FDI that has been consumed locally: it is an inflow of real output from the outside world.