Isn't eclipse a piece of tooling? I mean I think the best argument against teaching eclipse is IntelliJ is much better, imo, and is more widespread than eclipse at this point. Student should have a module/class whatever about command line tools as well. I this comparison is comparing two things that aren't comparable, an IDE vs learning the CLI. I also think you contradict yourself in your last sentence. Teaching an IDE in class should help people be comfortable with their tools but at some point they might need to know what the tool is doing under the hood.