You can pick your family but you can't pick your friends. As soon as the ring is on that finger, you can leave the old and cultivate the new. To do so, however, no matter which way you turn, is to enter a narrow domain of associations in which you are not free to not freely associate.
It's not team playing that gets you ahead but how well you can fit in. The families you pick ultimately determine who you're going to get into Facebook arguments with, just as Twitter battles will result over the alienation of special interest folding around the corners of differentiation. We can pick our trade but not how to trade or how to treat those we are trading with if we hope to complete the transaction.
The fact that 'networking' has so firmly established itself in our vocabulary points to just which parts of the economy we want to keep in a DIY culture... We certainly will not identify with those who can get us a leg up, lest we become simply leg-ups for others and nothing more.
'Greater love has no one than this; that he lay his life down for his friends.' Who wouldn't want a friend like this? It's just that few are willing to be that friend.
But we would die for any of our friends before we would ever be willing to cut the toxic ones from our lives. We would rather keep our friends list high and suspend the emotional privation which forced us into social media in the first place. We get worse at making friends as we get older because we get better at social media. Dying alone is a novelty only the few and privileged can afford. City dwellers see having the same friends in old age as they did when they were young as an indication of the greatest existential failure - the signature of one who has not taken risks. Likewise, the lonely world traveler wishes he never left to fight in the Trojan War.
The common platitude that one best keep a small, intimate group of friends is not wrong, for it emphasizes the alienation of valuing friendship in a quantatative way, the sheer inflation of number representing our eternal need to be attractive to non-friends for the sake of further social accumulation. The more you are to everyone, the less you are to any one.