Flag worship? Heh, heh, heh. Good point. I like George Carlin's comment: (paraphrase) the flag is a symbol, and I leave symbols to the symbol-minded. (say it out loud to yourself)
I think the sneaky point, though, is less "...to the flag" and more "...and the republic for which it stands." I think that was the devious part. Before anybody howls, I grew up saying the Pledge of Allegiance in school. In fact, in elementary school, I recited the Lords Prayer with the rest of the class. So, having been there, I have standing to evaluate the Pledge of Allegiance. Back to the devious part. I think the devious part is connecting the flag and the government ("republic for which it stands").
So, why have a bunch of kids pledge allegiance to a government? Or, adults for that matter? My first question is, "Why? Are you planning something to which you think I will object such that you want to secure my allegiance before the fact?" Allegiance is nothing more than before-the-fact agreement to go along with government. So, I ask myself, "Really?" I've spent nearly a decade penetrating the fog, lies, evasions, red-herrings, strategic silence, and spin government has fed to me all my life. Now that I have worked my way through that BS, to the degree that I have--at great expense in personal time, thank you very much--it is no wonder they wanted my before-the-fact-agreement, my allegiance to the republic (government).
And, why pledge allegiance to the flag at all? The flag is the symbol of the specialized corporation known as the federal government. Why mention the flag at all? Why not just "I pledge allegiance to the federal government." There is no reason at all to fog up the entity to which allegiance is being pledged--unless the motive is to fog it up.
It really boils down to getting people to pledge allegiance to the federal government.
When you get right down to it, its just plain nasty. No. Its worse than that. Its North Korean.