By limited choices i meant that restaurants don't have a lot of gluten free food to offer. Sorry if it was convoluted. Restaurants are starting to have req'd training in gluten allergies, which is smart because 21 million people accounts for significant missed profit opportunities. Their loss. Anyway, I completely agree with the fact that restaurants need to be more conscious of food allergens. 150 million people in the U.S. have some form of chronic illness that will restrict their diet.
The GIG (Gluten Intolerance Group) has a program called GFRAP that trains and certifies restaurants for gluten-free food prep. They have a listing of them on their website. It is still a good idea to check with the restaurant staff because their program does not include ongoing monitoring of compliance. So staff turnover or management changes could degrade the restaurants performance on gluten-free prep.
Your are right that more could be done. People with diabetes may need low carb diets. And there are plenty of people with food allergies also And people with heart problems are often on low fat diets.