(1) I seem to remember that the Lockerbie bomber was found because a piece of a circuit board used in the bomb was traced back to him.
If enough of these gadgets are sold, that police technique will no longer work.
(2) even though modern electronics are quite compact and vastly exceed the capabilities of these, there are lots of gizmos that work perfectly well with 15 or 20 year old technology. Completely clandestine versions of some things could be useful to people who do not want to come to the attention of law enforcement. This is not necessarily bad. A resistance movement in the case of an invasion would find these items useful.
True. In fact, in many pieces of equipment, even from 20-30 years ago, one opens up the chassis and finds inside mostly empty space...
Now, whether one of these printers can presently compete cost-wise with some PC board prototyping outfit may be another story. But in many cases, next-day possession of a prototype PCB could be quite helpful. I’d think well-heeled hobbyists would be interested, in some applications, too.