In this case, it's seemingly some co-workers that objected and not random other people on earth. More than those few cubicle visitors knew what this person was

In this case, it's seemingly some co-workers that objected and not random other people on earth. More than those few cubicle visitors knew what this person was working on. And the sniper story is just one story, there are loads more stories with other details that a co-worker could likely use to identify the person. A pseudonym does nothing.