I'm going to go on limb and say that if it wasn't for the George Reeves TV series, "The American Way" would have possible been seen as a short lived part of the Truth And Justice slogan used for the WWII era Superman and not as iconic as it is today.
Very good point, but every media incarnation of Superman has added huge pieces to the Superman character that have stuck around till today. From Radio bringing in Kryptonite to the subtle Lois Lane referring to Clark as "Smallville" in the Bruce Timm cartoons
Doesn't bother me one bit. The guy saves LIVES. Doesn't matter where that life is from. Saving the earth and all its inhabitants is what he's all about. The guy goes to alien worlds and saves lives when he's able to. He fought for "Truth and Justice", and was the "Champion of the Oppressed". Not my words, but from the creators themselves. "The American way" bit was tagged on in the old George Reeves Superman show in the 50s during the whole Senator McCartney anit-communist witch hunt. Back when everybody believed it was America against the world since supposedly every other country fell into communist hands. He was originally considered an honorary citizen of every country so I'm not sure why DC didn't just go with that angle.