It's really about blasting advertising and hiring good enough cheap. The engineers with a network will know not to go through your process and would expect a salary appropriate to the job, the ones that developed a lot of skills on their own with no network (or afraid of honest discussions with peers where they might not be the best) will settle for what they are offered.

When I look at who from my network (or really missing from my network) is at the places with these tactics.. Losing time and failing to get the job is not the worst outcome.