He wasn’t silencing anyone. There were no black suits with billy clubs outside.
He was warning the kid that if he went around repeating that aloud he’d burn himself on the interview trail as someone too naive to tow the corporate line and likely to reveal embarrassing workplace details to outsiders.
He was doing the naive youngster a favor, before he could hurt his own career.
The use of the phrase “people like that” is pretty much always pejorative, in a story where a guy who owes the student absolutely nothing took a moment to warn him “don’t touch the stove, you’ll burn yourself”.
So it’s become a story about government contractors instead of a story about “how I fucked up my job search as a new grad.”
Thank you, random kind recruiter guy.