AITA for not inviting my nephew on vacation

For the last 20ish years, I've planned a family trip. I love to travel and this is a way to include my siblings and their children (10 ppl) in my passion and a fun way to spend time together. I cover the cost of the tour and transport to the destination and they cover the tips/incidentals. So far, we've gone to Turkey, South Africa, Viet Nam, Croatia, Panama, Mongolia and Iceland. It's typically about $4000-6000/person and requires months/years of planning and budgeting. I poll the family on their availabilities about 18-24 months prior to the planned trip.

My nephew (late 20s) has RSVPed yes for the last 4 trips, only to back out at the very last minute (the week prior) such that I can't recoup the cost of his fare and the reasons he doesn't make it are never acceptable for a travel insurance claim. (work emergency (he's an accountant), friend's wedding, concert tickets, high school 10 yr reunion)

I'm currently planning a Galapagos cruise for October 2026 and decided not to extend the invite to my nephew because he's so unreliable.

Now most members of my family are outraged and, though not actually boycotting the trip, incessantly vocal on their displeasure at my 'targeting' my nephew.

I've tried to compromise by requesting that he give me a deposit with the plan that I return it if he actually comes but this only seemed to make people angrier. I mentioned canceling the entire thing and now only my younger sister is speaking to me. She tells me that the family is in uproar about my "selfishness" and discussing "writing me off permanently" if I actually cancel the trip. I'm in tears and just don't know what to do. I love my family.

Was it asshole move to exclude my nephew?