Ok, I went a bit far with my "why" questions... You're right, of course most people don't travel just for food. I don't either, and so don't assume everyone does. And you're even more right, there is more to life and travel than just eating.
But the OP and my post were about the same specific topic: food when traveling. I answered
this topic "im-very-ho" (meaning anyone can respectfully disagree) and yes, I'm honestly serious (a light kind of "serious": life shouldn't be taken so seriously!)
So, I'm puzzled about how one can chose to travel long journeys and state than going local is ok for a weekend or a week but not for more. I'm also puzzled about how one can travel a long journey and not "go local".
Food isn't everything, but we do eat several times a day and so it's a big practical part of any travel. In a deeper (personal) perspective,
traveling is to immerse oneself in a country's way of life... food included. It's just part of it: a pork-addict will have an hard time in Arabic countries, a vegan in nearly every country. Different eating habits are something to accept when traveling. This plus the personal view in which I also consider self-cooked meals as "local", because one has to buy local stuffs to make them and because they always somehow have a taste of the place you're eating it from. Family dinners, groceries stores and markets are such a specific reflection of a country's eating habits! And there is so much more to eating habits than just food!
I don't mean to say everything is good, attractive or that one has to try everything and eat traditional menus all the time. There are things I wouldn't want to try, other I just can't eat without getting sick ; I've been tired of national traditional menus and I've missed my own national specialties. Eating when traveling can be a need difficult to deal with... But I've always found enough diversity to eat well and be happy.
But again, I'm puzzled about the statement that Spanish food isn't diverse enough. Apart from the Menu del peregrino, there are large and diverse possible choices to pick from... and they're usually tastier!
On a lighter tone, I'm also puzzled about going to Burger King when saying there are too much drowned-in-oil food...