I don't really care how other people are dressed (within reason). Badly behaved is another matter.

Last week we ate in a two Michelin star and a three Michelin star restaurant in San Francisco. Both were jacket suggested for men. About half of the men did not wear jackets and some were a lot more casually dressed than that. One of the more casual tables were taking a lot of pictures, including flash, which was annoying, but they stopped after a bit, perhaps because someone said something. In the other restaurant, a nearby couple were very well dressed, but loud with a self-important tone, gossiping about business colleagues. Mercifully they came in as we were finishing. Everyone else was well behaved, so far as I could tell.