There's a basic human need to be valued by others and to be part of a community, and the system we have now grades people according to traits that are mainly genetic and casts them aside if they aren't seen as desirable enough. As for what the cut is, well, it's many-faceted, but the waterline is rising and as you age all of your desirable traits are fading. If you have real personal relationships (either career or friendship-related) you've escaped it for now, but if anything ever happens to reset your network and cast you back into the default pot, you might get a chance to experience it.