It has come to my attention that people these days don't know what to do when they are asked to RSVP. Either that, or people are just plain rude.
I get this a lot with events at work. We have a limited number of free seats to give away to important guests, so we ask the people we invite to RSVP. Half the people don't bother responding, so we assume they're a no and give those extra seats to people who perhaps should have been on the original list, but didn't make it because of space issues. Then on the night, all these people show up, often with partners even though there was no mention of a plus one on the invite, and people who did RSVP saying they would be there, don't.
Today my son had his birthday party. We invited 6 kids and asked their parents to RSVP so we'd know how many to expect. I got two RSVPs. No one else even bothered to call or text and say no, we can't make it. If I'd known so few kids were going to come, I would have let my son invite more kids. He hasn't said anything, but how sad must he be that only 2 kids came to his party? And no one even bothered to say that they couldn't make it?
Is this something you've come across? Is it acceptable not to respond these days, even when specifically asked?