In addition to what other people said, some companies use it to screen out people who are going to cause employee conflicts, ie, are you using it to make controversial posts and comments and say things that violate the social contract, or do you use it to communicate with family and talk about your hobbies?
If you don't feel some attachment to your past and want people to be able to find you and contact you, in this age without phone books, are you going to be a company person? Or do you just want a paycheck?
I guess I don't see social media the way you do....I've never thought of not having social media as the same thing as "no feeling attachment to past or want people, etc".
I've never done social media, yet I'm in almost constant touch with friends over 45+ year I've been with...we text, phone call, email...and actually try as often as possible to get together in meatspace.
Anyone that needs to know where I am...knows where I am.
And not sure about....company person? I mean, the ONLY reason I work...is for $$$.
I've contracted 1099 and done W2 over the years.
When I go to work, I follow the rules, I'm very amiable with co-workers....I do work stuff at work and when the door hits me on the ass on the way out, I leave work fully behind.
As a general rule I do not associate with co-workers outside of the office. I have real friends for friend actives and needs....I have found over the years, it keeps things professional and keeps problems at bay.
Frankly in the litigious society we find ourselves in today....I do believe employers are looking more for a person like myself...little to NO threat of interoffice conflicts or lawsuits.