It's not about "having a life outside of work". I have friends in several different social circles. Some of us still desire a concrete separation between pers

It's not about "having a life outside of work". I have friends in several different social circles. Some of us still desire a concrete separation between personal and work lives. Not only that, but some of us find there are significant benefits and upside to being able to socialize with our teammates and even management because those work relationships are great resources later. Someone is much more likely to want to help you get unblocked if they've formed a connection with you before. Otherwise you're just "that other person working on that other project and since it doesn't block me from my work then why should I spend any time, despite having the prior experience to assist you"? And that's just one example.