When you say “family has to come before beach house” I’d agree if he said he booked beach house for himself or to do drinking with some guys, then I agree. But beach house is his family outing, he booked it for a family. So he is really not prioritizing beach house. He planned something for his family. Perhaps he prioritizes immediate family over extended. That’s not uncommon and I don’t see how it makes him shallow

If you want everyone to attend big events like weddings or graduations. you plan like a year in advance but even then you might have people unable to attend. Typically graduations are not attended by 100%. It’s not uncommon for people being unable to attend

Your feelings are valid. Intensity of your anger is a little unusual though and it makes me think there is more to the story. You shared ongoing difficult relationship with your own and your husbands family members and with other people (neighbors classmates friends etc etc) before. maybe there is general animosity in the families and in your circles or maybe there is something else at play