Having milk is a big deal to us. Both my boys are fine with just water, and most nights, I really don't want them to drink some sugary glop.
My older son is more adventurous than my younger, but when we go into a place, if there is the cr@p that is on most kids' menus (some kind of fried chicken thing that is either a nugget or a "tender") he will go for that. And this is a kid that loves frogs legs, all kinds of Chinese food, tofu in most forms, most raw and cooked vegetables, etc. But he has been programmed by being around other kids that those are the things that kids eat.
I will say that I push my kids way more at home and I want them to learn to go out and enjoy themselves at a restaurant. I do have to echo that simplicity is best for kids - sure smoked, or truffled, or with bacon makes mac and cheese special for an adult, but not for a kid. Not hard to figure that one out, I guess.