I suppose this depends on the type of restaurant. You're never going to see a picture on the menu of a high end restaurant. In the same way that people equate a screw top with bad wine (even though it's about 10 times better of a technology than a cork) people will always equate pictures on a menu with Olive Garden type restaurants.

Also the really good restaurants base their menu on what's fresh that day, so pictures wouldn't be practical.

And I think that people who are intimidated by the lack of pictures on a menu tend to mostly dine at the places that have them.