Because to view any Facebook event page you must agree to a Nondisclosure Agreement that restricts you from revealing the particulars of the event to people who do not have Facebook accounts.
Because there's so much more friction involved in including people who don't have Facebook accounts that, eventually, you just stop bothering to do it.
Yes my last high school reunion was like that. (i.e., people who weren't on facebook weren't invited, even if they were known in the community and available at phone numbers advertised to the public.) Their loss!
I wonder if that is why I didn't hear of any high-school reunion yet. Last year was my 10th anniversary of graduation. (Although, it might just be that reunions are not as common in Germany. Maybe noone bothered to put one up.)
My wife and I hate Facebook and aren't on it; and yeah, we sometimes get miffed when people assume everyone who matters (or close enough) is on it, and use only it for communicating with family, friends, a social club, or whatever.
We're the kind of people who are _proudly_ not on Facebook, and not at all shy about it. The only social network worth a damn is LinkedIn, and only so long as they are useful in finding work.
Hard to fake a heartfelt, mortified apology. That's the thing - if I'd been deliberately snubbed, I wouldn't fuss, because generally when that happens there is a reason for it. But one doesn't receive an apology when that happens, either - especially not such a shamefaced one.
This was just that Facebook's walled garden expanded to surround my erstwhile social circle, and once that happens, you maintain your presence in that circle on Facebook's terms or not at all.
To how many mainstream-culture American weddings have you been invited? It has been more than a few for me, and in general the (printed, hand-signed, often hand-decorated, mailed) invitations are fussed over by the bride and her mother nearly as much as the flowers. All of those brides would have been mortified at the suggestion to just leave it to facebook...
Quite a few, including my own. No one I've ever heard of has actually used Facebook to send invitations. But, in at least two cases over the past four years, Facebook friends lists have been the only source used in constructing an invitation list. Not being on Facebook, I wasn't in those lists. And so...
I mean, I get that it's hard to believe what I'm saying can possibly be true. I wouldn't have believed it myself before I saw it happen! It sounds like something out of the kind of third-rate sf dystopia that fails to achieve much popularity even among genre fans. But here we are.
Only source? Wow! That's tragic for grandma, but I guess some weddings are better off without old folks anyway? b^) Actually, in a couple of years that will be a good way to leave out young people...