In Japan, McDonalds is the number one place for high school kids to do their homework, it seems. They spend hours there.
McDonalds around the world tends to be much better because they localize parts of their menu. Like, in India, you get "paneer tikka wraps" which are rather tasty. I can definitely see it being a popular study place if the prices were still dirt cheap (although, I don't think a satisfying meal is so cheap anymore in USA McDonalds).