Interesting article, and from my experience, I would NEVER recommend someone go into the Navy undesignated. I would tell them, when they are talking with a recruiter, make sure they have a school. It is true, undesignated Sailors get the crap jobs as Seamen, Airmen, Firemen, and probably Constructionmen. The problem with being undesignated, is you can't be a Petty Officer 3rd Class (E4) as an undesignated Sailor. Before I retired, undesignated Sailors were given the opportunity to "Strike" for a variety of Rates, based on their personal desires and qualifications. They also had to pass the Advancement test for the Rate they were wanting to Strike for. Some Rates do not qualify for this process.
When I was in my Cryptologic schools, we had a few Petty Officers that "rocked" (failed) out of nuclear power school but had to get a school for a Rate, because they were gifted E4. Granted, NUCs are probably the cream of the crop when it comes to "smarts".