In my experience, a lot of people do in fact enjoy going out to eat for the food, not merely the experience. You get a professional preparing excellent food, usually to a standard higher than you would easily manage at home (assuming you're going to good restaurants), and in a wider variety of cuisines than you can affordably stock up for, too.

Expansion on the previous point: I bounce around national cuisines quite a bit, because I'm a cook as a hobby, and whilst, say, a gumbo won't cost you mutch if you're regularly cooking Louisiana staples, cooking it ab initio from a cupboard that's normally cooking Italian-influenced meals will cost you a small fortune. A quick look at my Louisiana recipe book tells me I'd need to aquire cayenee, paprika, garlic salt, onion salt, white pepper, spiced sausage, Tabasco (specifically Tabasco) and a bunch of other stuff. Then you need to get in all the meat and veg, some of which may be difficult to aquire from local shops or require specialist outlets, which adds in travelling time and cost, and which you'll probably be paying for higher quality for - at least if you're serious about cooking and food - than you might for a common-or-garden meal. That makes your one gumbo cost almost as much as it would at a restaurant.