Thinking this one through, it seems what I personally don't like about these events is the level of social expectation placed upon them.
Hence an informal meal in a restaurant for a birthday, even with a large party of friends, I'd enjoy. Weddings not.
Easter/Ostara/Spring holidays, I enjoy. There's no conventional duty or expectation associated with it, we can go away or stay at home as we prefer, and it's a fraction of the work and planning associated even with simple Christmases.
Research based conferences I thrive on, and have organised and hosted plenty of them as well as attending as a delegate. My participation is entirely optional - and as a rule I opt in. Because I can go along, have a great deal of fun with like-minded colleagues (the socializing is brilliant) and can actually learn something.
Compulsory strategy team-building and away days, I loathe with a passion. They are a big investment in time because they never actually achieve anything worth knowing. My organization hosts at least four of these things a year and I shudder at the thought!
I admit there's an element of the childish rebel in here, too. It's about being told what to do: 'your attendance is expected', and when you do go it will be exactly the same dross you've seen about two dozen times before. Because ... 'it's just what you do'.
Not enjoying precision-organised, 'traditional' events isn't misanthropic, and it's certainly not a crime. It's really silly to take offence at someone not enjoying something you do, and vice versa. It would be a very boring world if we all liked the same.