What is big fat deal when someone unfriend you on Facebook?

[TheErrandBoy]

Anyway, a married friend whined to me and was upset when a woman he got to know in pub unfriend him on Facebook after he did not attend her birthday. I don't get what is the big fat hairy deal about being unfriended. He acted as if he lost something big and it was like end of world, WTH. Am not a Facebook user but IMHO, Facebook is turning matured guys into whiny gossipy people who sweat the small stuff. Geez. There is just too much irrelevant silly trivial nonsense with excessive use of social media like Facebook, Twitter that people have allowed it to invade their lives and their privacy.