I hear this all the time as well, Tom. Most people don't understand at all how things are made, and that most of the things around us are made from plastics, not metal.
Even then, 3D printing is just weird enough, outside the scope of the experience of most people, that unless you've done hand-on work in it, it's hard to see the value.
James Burke (BBC presenter and historian) said in his "Connections" series that around the late 1960's, things made of plastic became their "own things".
Previously, items made of plastic had to imitate some other existing thing for them to be accepted. Notebook covers had to imitate leather, complete with fake stitching. Telephones had to look like the older ones made of Phenol resin. And so on.
3D printing is at that stage right now. We're using it to imitate items made in traditional ways, and not treating it as a new process in it's own right. But given time, people will adopt it as something totally distinct from subtractive manufacturing.
Absolutely. This will be another big year for 3D printing coverage in the media so hopefully educating the public continues. And it almost seems like schools are the best place for 3D printers because there isn't the barrier of expectations and criticisms from adults.
Even then, 3D printing is just weird enough, outside the scope of the experience of most people, that unless you've done hand-on work in it, it's hard to see the value.