A small injection molding machine will still require an in house CNC machine for creating tools, and that’s prohibitively expensive for materials as a student. Students can learn as much about injection molding with a good teacher and a weeks lesson in drafting plus sketches. I would also argue that theres very advanced tooling approaches (we commonly had parts with pulls/slides/cams in all 4-6 directions) that allow very wacky things to be built. Not to say students shouldn’t understand those things, but early on in your career you can also be limited by a smaller amount of knowledge and thinking everything needs to be an A-B tool.
With that said, I had a girl in my ID studio in college design a bucket for horse shit (literally) and then when asked what it was made out of her response was “Carbon Fiber, because it’s light”. Needless to say her ID career never took off. 