There are many thing that the citizens of the United States are well known for, or stereotypically known for. For tourism, they are known for being rude, obnoxiously loud, picking on locals, and wearing brightly colored clothes. In other international aspects, Americans are known for invading and destroying countries under the guise to help.
Despite all this and internal problems, one thing Americans are/were known for is patriotism. To be proud of an American. In this recent generation. many liberals seems to hate this country and will commit acts such as burning the flag. The kneeling under the anthem represents another aspect of disrespecting your own country.