Books that "foster nationalism", or any other set of values for that matter, are imo precisely those that can grab the attention of many people through emotional connection to characters who act in specific (politically non-neutral ways) ways. It works well when the reader does not think of the content as political in nature. There is some sort of a strange tendency in some layers of society to view books as inherently more politically progressive and otherwise more mature and beneficial than television. This is a result of a misunderstanding and constitutes little but usual intelligentsia snobbery. Yes, some books do make you think more than most moving images, but those books are nowhere near the mainstream of the publishing industry. One also has to remember the relatively young age of the moving image technology and its higher costs.
On what grounds do you claim that tv watching is mainly about "connecting to something bigger than yourself" in a way novels aren't? I don't understand.
Cult movies are good examples of motion pictures that were turned into (theatrical, ritualistic) close resemblances of written texts. They are broken apart, taken out of context, paraphrased etc - fans treat them the way one traditionally treated a written text. Also, think of tabloids. No connection to bigger than life celebrity life?