Those very students were taught the skills they would need to work in a factory, because that, statistically, is what most of them were going to do. Times have changed again. We are now embarking into a new era, the Technological Era. Just as there were many reasons that people needed to have agricultural skills, so are there many reasons that students must be taught technological skills. A very basic reason that technology should be included into curriculum is the fact that it is becoming part of the Educational Standards, along with reading, writing, and arithmetic.
Technological skills are also now a requirement for most professional jobs.
Finally, technology is the way of the future. We have only just touched on the possibilities of technology. Little Johnny doesn't need farming or factory skills any more. He is going to need to know how to read, write, and solve basic math algorithms. He is also going to need to have technological skills, otherwise he is going to be left behind, trying to survive on skills from a bygone era.