Yes, him nonwithstanding (you’re forgetting that Key wrote about the war of 1812, not the Revolutionary War. In addition, the story of its composition is oft misunderstood: the same flag did not fly through the night, and that would have been silly: they flew a much smaller storm flag through the night: they hoisted the now famous flag in the morning as soon as the weather cleared, and THAT was what Key saw from his vantage point 8 miles away) Key thought the war was the fault of the U.S. and that we deserved to lose it: he wasn’t exactly mr. patriotism, and his song was not by any means immediately popular. It was not adopted as the national anthem until 1931. It wasn’t popular in the military until 1890, when the army and navy bands popularized it (it’s always been a better big band tune than a easy to sing anthem).
As I said, the flag wasn’t flown in the Revolutionary War, all patriotic pictures to the contrary (fife player, Delaware crossing, etc. many of which, ironically, were painted not to inspire Americans, but to inspire Europeans to revolt like the Americans had) Not a single land battle in the Rev war was fought under it. The only well known hero who fought under the flag was Captain John Paul Jones on the Bonhomme Richard (and even a number of silly myths abound about that)
Betsy Ross did not create it. It wasn’t flown from government buildings. It wasn’t up in the schools. It didn’t appear in newspapers or paintings. John Adams and Ben Franklin didn’t even know what the flag looked like even a few years after it was official established: describing to foriegn dignitaries as having alternating red white and blue stripes. Even though its look was set by Congress, people gave little heed to its design for decades: you’ll find military and militia flags from that era that look nothing alike, from the number of star points to their arrangement to the number of stripes on the flag. No one really gave it much attention. When the idea came up in Congress to amend the flag with more stars for additional states, there was a huge cry that it was not a matter worth the time of Congress, and it was passed just because that was the quickest way to move on to other business.
It wasn’t officially carried until the Mexican American War. The marines did not adopt it until 1876. The calvary didn’t until 1887: Custer’s men never carrried it into battle, as has been variously portrayed regardless.
The idea of countrymen worshiping a flag didn’t arise until mid-Civil War, when national symbols of unity were deemed important for garnering support and patriotism and stopping people from joining the rebellion. And it didn’t really catch on until proto-facism became the worldwide norm: the idea that everyone must worship their state and its symbols. As you can read in public statements of the Daughters of the American Revolution, the major emphasis on these patriotic traditions was to try and turn the hordes of immigrants into proper Americans and try to ensure their loyalty. This even sort of exists to this day in the citizenship tests that demand knowledge from prospective citizens about obscure patriotic rituals that few naturalized citizens have any knowledge of.
Schools were not required to fly it until 1890. There was no pledge until 1892 (and then it was a very very different pledge than we say today). Saluting the flag didn’t begin until the Spanish American War in 1898. Flag Day came in 1916. And the flag code didn’t start until 1942 (when we stopped saluting the flag with a raised palm because it was too similar to the Nazis), and wasn’t even federally recognized until 1976.
The fact is, the people of the Revolutionary era were not as big into sacred national symbols as we are today. That may be hard to grasp, but to people of that era patriotism meant doing things, not saluting things. Flag worship is an entirely modern development.
Well, I could say that you could just pick up any decent history of the flag, as there are many. But Milo Milton Quaife’s The Flag of the United States (1942) is an old standard. You can also verify the dates I gave (like when the marines adopted the flag) since they are simple matters of public record.