When we travel you can usually count on us hitting up a McDonalds or Starbucks where ever we are. Why is that, when at home in the states those are not places we hardly ever eat at? A couple reasons: 1) it's food from home and 2) it's pretty darn consistent.
Sure, we can get a pizza most places we go but you never really know what you are going to get (clams and corn on the "meat lovers"? Yeah, that happened). If you are looking to order favorite foods from home it is best to have your expectations set low; it often comes out at best with something not quite right, and at worst just all wrong. But at McDonalds that quarter pounder and French fries is about the same where ever you go (except of course at places that don't serve beef, then you've got interesting new things to try like the McVeggie. It's also fun to see the local additions - taro pies in Taiwan for example). I can order my Starbucks drink, in English no less, anywhere and I know exactly what I'm getting. So while it's not necessarily what we'd consider good food, or the food we miss the most, it is familiar and there is something comforting in that.