[6d0debc071]

Mmm. There's a connotation with shields that they are just as you say, protective in nature. There's consequently a negative association with their removal. However, the person's still being protected from undesired input while they're looking for a job: The criteria for desirable/acceptable have changed. Their 'shields,' using those criteria, are still up.

It's a tricky analogy that, as you note, is easy to misunderstand. The writer may not have meant it in the sense that it was received.