Nutritionally, there is no good reason why black soldier flies cannot be directly consumed by humans rather than being first fed to some domesticated animal. Perhaps sometime in the future, BSFL burgers will become a common item in fast food establishments. However, currently technologies for mass production of black soldier fly larvae are being developed mostly for animal feed. It is likely that such an approach will persist in the foreseeable future.
First, there is a significant “yak” factor. There is a considerable reluctance among large segments of the human population to partake insects in general. It is somewhat irrational; nonetheless, it is an important factor that cannot be disregarded while promoting entomophagy. Therefore, telling people to eat gross maggots living in stinky decaying junk is unlikely to be very successful. To the contrary, it may become associated with eating insects in general and serve as a deterrent for a wider adoption of entomophagy.
Secondly, given that one of the great benefits of farming black soldier flies is their ability to recycle a wide variety of wastes. However, using waste as larval substrate creates understandable food safety concerns, which may not be easy to address.
These challenges may be overcome in the future. However, we are not at that point yet.