That was exactly my point, Tendon. It's a bit like on another thread where people were supporting someone whose entire friendship group bar two had apparently egged her on to have a 40th birthday party, and then a couple of days ahead, had all sent stupid texts crying off at the last minute with limp excuses. She was really upset and rightly so. Her friends had behaved very badly and treated her appallingly.
Relationships are supposed to be reciprocal. Social engagements are supposed to be reciprocal. A lot of things in life work best if they are reciprocal. There are well-established rules that help the wheels roll smoothly in relation to such things. One of these is not accepting a better offer once you have accepted an invitation, and then making every effort to attend. Another is remembering that while you are entitled to organise your wedding day to suit yourself to a large degree, this shouldn't be at the expense of the sanity and well-being of your guests.
However increasingly we ignore many of our social rules - sometimes this can be useful, but sometimes it can be harmful. Starting to be very selective about who is and isn't allowed in church for weddings services is, I would argue, harmful, for example. It basically promotes intolerance of groups of the community, perhaps along with those pesky disabled people with their messy wheelchairs and potential calling out, and those annoying elderly relatives with the beginning of dementia who don't look quite stylish enough and who might say the wrong thing at the wrong time, and so on and so on. It is not only ungracious to reject great swathes of the community like this, rejecting anyone who doesn't match up to your high standards is actually pretty toxic if it's allowed to flourish.
If people abandon thinking about others and get obsessed with 'their' day and what they want and making everyone else fit in with that, by hell or high water, there comes a point where it ceases to be a joyful thing and starts causing wider problems and anxiety. And that is a good reason for people to seek more in the way of compromise rather than simply be dismissive of the needs and situations of others.