In the past, I've seen examples of D-shell connectors with molded all-plastic connectors. The most common example is perhaps the Atari 2600's molded female joy

In the past, I've seen examples of D-shell connectors with molded all-plastic connectors. The most common example is perhaps the Atari 2600's molded female joystick connector, but I've also seen male iterations (usually on IDC connectors). Other than lack durability and lack of built-in shielding, I don't see any problem with the idea of 3D printing such a thing. With a decent resin printer, one should even be able to design it to use removable pins that just snap into place (which are things that are still made in factories every day).