Shimauta

The students in my English class are learning about Okinawan music and specifically a song called "Shimauta." Today the teacher handed out a paper explicating the meaning behind the lyrics, which is basically the part below the blue text on this page:

http://www.enoshimairuka.com/shimauta.htm

the top of the page shows the page writer to be quite Anti-American so what I'm trying to find out is: is that really the intended meaning behind the song or something the page writer made up? It seems to fit the lyrics pretty well. Sadly, it wouldn't surprise me if this particular textbook had a song in it with that meaning, but it would be a shame because it's actually a really cool-sounding song.

Don't worry. People have born, lived, loved, died and sung.
I also notice people like the guy seem to use anything if he want to claim what he believes, even though he infringes the copy right of Kazufumi Miyazawa, original singer of Shimauta.

You are studying the song in your english class? Interesting, I wonder
how it translates into english.
I can't imagine who wrote that article above the song, but I'm pretty
sure Miyazawa never wrote that song with anti U.S sentiments.

The song was hugely popular worldwide, especially in South America and
Russia.