It’s a chain restaurant. Funny thing to build family traditions around, it’s not like a 300yo family run pub that has been serving a community for time immemorial.
People here on HN complain about tech companies losing their charm and they're giving up and switching to another OS/phone/whatever, and get very upset because (company) is losing their character and everything that made them unique. It's a funny thing to build an identity around a trillion dollar company.
But yes, people have things they like. They like when things they consider good don't do total overhauls. There's a very good chance you have something you hold dear or would be upset if it changed, and others will happily mock your frustration.
It's a restaurant chain having a rebrand. I've no sympathy for this absolute childlike behaviour, and even less sympathy for people trying to pretend that the outrage was anything but artificially stoked.