I take it as just a joke, not as Douglas Adams pointing out no job is useless, because management consultants were included too and I can't see him think THEY are useful, but it's possible.

My takeaway was the people who would decide entire swaths of society were useless were also idiots.

Whoever decided to downvote a thread on the Hitchhikers Guide of all things rather than join the conversation is an embarrassment to the profession.