Boss forbids supervisor from eating lunch with his employees because he thinks that socializing with subordinates will compromise work performance: 'I truly have a sick, sociopathic boss.'

Shouldn't he want his employees to build close relationships with each other? 

Everyone has a different opinion on friendships in the workplace. I know people who only hang out with their coworkers and don't have any other friends. They will go to Happy Hours five days a week and intentionally hang out with their coworkers outside of work hours! I can't imagine living that life, but if it works for them, then more power to them! Having friends in the workplace can be either really helpful or hurtful depending on how it works out. If you are able to maintain those relationships, they will be an important member of your network for as long as you live! If you and your friend have a falling-out, it's going to be awkward when you have to see them at the office five days a week for the foreseeable future. 

Most of us are friendly with people at work, but aren't trying to make our work friends our best friends. You can give the PG story of what you did last weekend, but you're not going to tell them all of the crazy details. That is probably for the best. It helps you connect with your coworkers emotionally without compromising their perception of you as a professional. You don't want to end up as one of those people on the workplace harassment training video, do you?

A lot of workers don't like having any kind of relationship with their coworkers at all. They go to r/antiwork and talk about how annoying it is that we're expected to be friends with our coworkers in order to stay employed. Well, the guy in this story didn't do that. He took to r/antiwork to complain that his boss's boss didn't want his boss to eat lunch with his subordinates, aka him. Did you get all that? Don't worry if you didn't; it'll all make sense if you scroll down.