"It is simply that those profession are all, to one extent or another, trained observers, sir. The very sort of people adept at dealing with an emerging crisis and tackling the unpredictable. Many have some form of martial arts training too. All in all, they represent a formidable prey...the prey that would fight back and be likely to identify something amiss if one's Blush of Life were slipping, for example." she smiled sweetly.
Keen to establish a tone of careful explanation, rather than lecturing.
"They also have robust and expert investigative resources that would be most hazardous to the Masquerade should something dreadful happen to one of their profession. It is best to simply leave them alone." she smiles sweetly. Confident she's made a fair point.