I'm at my grandfather's funeral today, and literally half the people there were wearing something I thought was completely inappropriate. One dude was wearing a fucking batman T-shirt and fucking jeans. My cousin was in a full blown cowboy get up complete with jeans, flannel, cowboy hat and boots with a giant ass belt buckle. Keep in mind this kid was born and raised in northern Michigan. He hasn't rode a horse a day in his life.
Now I'm not expecting everyone to show up in a suit and tie but to me, jeans are absolutely unacceptable funeral attire.
The culture is changing. Many businesses don't require employees to have a suit jacket or tie, so why would they? I was born on the west coast 60 years ago, and only church-related activities required dressing nice. Even that eased off. When I first moved to the east coast, suit and tie was normal every day attire. Now, not so much. I do agree for things like funerals there is a lower limit, and it sounds like a few people slid in under the line, but for a lot of people, as long as the jeans are clean, and the only tears were intentionally done, that's formal.