I beg to differ. Other diners do care. When we see people wearing logo tee-shirts, casual shorts, and ball caps straight from the park, it takes away from the overall ambience of the restaurant IMHO. Most people dress well when dining at a signature restaurant.
We get ready in our hotel room, shower, etc. My husband wears a button down shirt and pants. He has worn Bermuda shorts with a button down shirt as well. DD and I wear dresses.
If I didn't want to go back to my hotel room, shower, and change, I would have my DH wear a collared polo shirt and khakis or Bermuda shorts at the very least. He would still be comfortable in the park. DD and I would wear sundresses and sneakers in the park and carry dressy sandals to change into before entering Cali Grill.
If someone doesn't want to make an effort when going to an expensive restaurant, then maybe they should eat at a casual counter service place in the park.