There are lots of restaurants in every city for folks aho don’t want to dress to standards. having standards does not necessarily mean you are snooty. It may be a way to create an environment that makes for a more pleasant experience for everyone. It might be a way to show respect for other patrons.
Demanding people wear a coat and tie to eat your grub is the very definition of snooty. You can create a perfectly fine atmosphere and not worry about how people are dressed. Honestly if you’re paying attention to how the other patrons are dressed, the food probably ain’t that good.