Sam is presented as British working class, and is arguably the hero of that part of the story. He is the least corrupted by the ring, despite carrying it and using it. And the Mordor chapters in Return of the King are all written from Sam’s perspective.

I agree that ruling classes are not taken to task; in fact they are celebrated throughout the books. On the other hand, the wise and powerful rulers cannot win on their own. Only the secret mission of Sam and Frodo could achieve victory.