the lost art of RSVP

it's fun to know the origin of some of our modern abbreviations.  for example, i didn't know--until my grandfather told me--that a tip, or "TIPS" that we pay after a meal originally was done beforehand:  To Insure Prompt Service.  and then there's the art of RSVP, from French "Repondez S'il Vous Plait" or respond if you please.  so it's funny that tips evolved to become evaluative of service and i'm wondering why we as a generation tend to rsvp less and less.  i guess people assume that showing up or not IS their RSVP, which means that responding beforehand--like handwritten invitations--is a dying art. or maybe, as i heard recently about this generation and the advent of texting, "they're just waiting for something better to come along" so are hesitant to commit one way or the other to social engagements.  do you know of any other abbreviation origins?