Yup.
I don't understand the article, are they saying the number of sales have decreased, or the value of those sales?
Because if it's the latter, it might be because now everyone just orders from the dollar menu to save money.
I used to pay $7-8 for a meal before I started buying from the dollar menu, now I usually spend less than $5. I realized I don't even want the larger portions, or the soda, so the dollar menu is perfect for me.
I read an article somewhere that this move to the dollar menus is (obviously) affecting the profits of all of the restaurants, because everyone is pinching their pennies now. It went on to explain how the sales on soft drinks have decreased, because many people ask for water now, which has prompted many to stop serving tap water and add bottled water to the menu.