For me, Will Kane embodies the American ideal of a hero: a man who stands up for what is right, even when nobody else does, even when the temptation is strong to stick the head in the sand.
Will Kane explains his outlook at the outset: there is no point in running away if that means spending the rest of your life watching your back. His best chance is to face his enemies on his home ground. At this point, he still thinks that honest folk will stand by him. The rest of the movie is a study in character: will he stand his ground when his entire world crumbles around him?
It is puzzling that Howard Hawks, John Wayne, and others thought of High Noon as un-American. I am not sure if this is because of the allegory of the McCarthy era; or the people of an American town collectively sticking their heads in the sand; or the Marshal throwing his badge to the ground in the last scene.
Clearly, the movie does not criticize McCarthyism itself. (It has nothing to say about communism, either.) It appears to criticize the people who did not stand up to McCarthy and the HUAAC, but it can equally well be seen as a comment on the appeasers who did not stand up to fascism or communism.
In any case, not too much must be made of the anti-appeasement angle, because the townsfolk is not the primary focus of the movie: the focus is on Will Kane. When the townsfolk behave like cowards, that gives Will Kane a chance to prove that he is a hero. If the town had stood by the Marshal, we would have seen, at best, an excellent Western like Rio Bravo, but not a masterpiece like High Noon. For Will Kane to be a hero, it is necessary that he stands alone.
No statement can convey the dramatic impact of Will Kane throwing his badge away, but it is worth discussing what this gesture means. For me, it means that the town and the badge were not worth fighting for. Will Kane fought for principle: he fought because he does not run away.
