I'm sorry, not entirely certain what you are asking here.
Are you asking us if we think that Independence Day is sincere? As an American, I am proud of this still even though I see so much idiocy in our government. I still love America and I love Independence Day.
Just like any other country that gained independence from a colony, US saw the significance of commemorating the day they got freedom from Great Britain on July 4, 1776. It is made attractive and fun by the patriotic displays and family events are organized throughout the United States. Many people display the American flag on their homes. For more details, visit http://web-holidays.com/july4/.
Of course it's sincere. We all should be proud of our independence and thankful for all of those through the generations who served to give us that independence as well as those who serve to maintain it!