Most bosses realize that fear is a poor motivator because it inevitably creates resistance and passive aggression. Fear also drives people to make dumb decisions out of panic. As one savant memorably put it: "Fear is the mind killer."
In addition, few bosses are intentionally sadistic. While there are some who like to see employees squirm, most managers know that it's easier to motivate people if you make the attempt to be likable rather than act like a raging bosshole.
Nevertheless, many bosses don't know how easy it is to make an employee feel panic and stress, especially when they send an email with content like this:
"Can you meet with me at 2 p.m. tomorrow?"
To a boss, this seems entirely innocuous. You have got something on your mind--something that's easier to discuss interpersonally rather than by email or text, so you want to set up a meeting. What could be more reasonable?
Unfortunately, when an employee sees a meeting request like that, it's like hearing "we need to talk" from your spouse. And that's downright ominous.
The moment they receive that email, employees' brains go into overdrive--wondering what they did wrong, whether there's bad news, whether they're about to be fired, etc. Productive work grinds to a halt and the cold sweat begins.
If the employee gets the email in the evening after work, it might easily result in a sleepless night, which means the employee will come into work in zombie-mode, which means more lost productivity.
Now, a savvy employee isn't fazed by such an email and instead will respond with something like:
"Sure! Could you give me an idea of the subject matter, so I can be certain I'm prepared?"
But not every employee thinks of that. I know I didn't back in the day. I remember getting that email on the evening before a long weekend; stewing about it basically ruined my entire vacation.
Ironically, that email is pointless even if you think fear is a good way to motivate your employees. Because the fear is undifferentiated, it can't drive behavior. All it does is drive the employee crazy.
The solution, of course, is simple: When requesting a meeting, a boss should always identify the reason for that meeting. BTW, this rule is also true for employees. While bosses are less likely to be paranoid, why introduce a dread of the unknown?