I imagine it depends a lot on the field. I'm in computer science, and while a few academic research programs need lots of programmers, mostly there aren't a lot

I imagine it depends a lot on the field. I'm in computer science, and while a few academic research programs need lots of programmers, mostly there aren't a lot of things that a relatively untrained tech can do. We need PhD students and postdocs to actively do novel research, publish papers, and chase grants. It's also really unlikely that we'd find anywhere near enough techs to make up the difference anyway. In CS, your options as a bright student are to go into research or go make a fortune for Facebook. We can compete with industry only because we're offering the promise of a career in research. If we had to staff the labs with people who had no desire to join academia, the costs would go up substantially.