Not just anyone is qualified to sing it
Chris Wade at Slate, apparently a Canadian sympathizer, complains that the national anthem is too hard. Tough, Chris. So is freedom.
You see, the reason I like the song is that exposes people who have built their careers on the lie that they have talent (see Britney Spears post below). Beyonce had no business in front of that microphone. For those who do not care to see such a spectacle, here is the solution: book an actual singer.
Marvin Gaye explains here.