I won't argue the Revolutionary war, but in my opinion, in WW1 and WW2 the UK was in practice a parliamentary democracy, even if it was/is 'officially' a constitutional monarchy.
You have much stronger feelings about this than I do, especially since I didn't write the original blurb in the post body to begin with.
We're just trying to get people amped up to resist our current regime, and I suspect the person who wrote that was trying to tap into that classic and slightly cringe 'Rah rah, America!" patriotism that we're so well known for.
EDIT: Ah, I see what you mean now. It took me a while to get what you meant since I consider the UK during WW2 to be a form of democracy. You may have technically still been a constitutional Monarchy, but it was a parliamentary democracy in practice, as they are today, and have been pretty much since 1928.
I won't argue the Revolutionary war, but in my opinion, in WW1 and WW2 the UK was in practice a parliamentary democracy, even if it was/is 'officially' a constitutional monarchy.