I don't agree that nothing can hurt Tom or that it is easy to be a pacifist
under any circumstances. Otherwise Tom would not be unique. Tom was
not a pacifist because of his immunity, but rather gained immunity because of
his pacifism. I refer you (and Pukel-man, if that was your point) to
letter 144.
Frodo does not become a pacifist until much later, I agree. But Tolkien
did say Tom was a pacifist, and represented the pacifist point of view.
Where else would Frodo learn about pacifism, if not from Tom?
And by the way, I doubt very much that Tolkien would agree with your cynical
take on pacifism. Merry might agree, but not Tolkien. I think that
Frodo eventually (not immediately, but gradually) reached such a level of faith
in Higher Powers that, like Tom, he truly believed violence was
unnecessary. And in Tolkien's fantasy, if not in the real world, Frodo
may be right.
I do agree that Frodo learned from Tom "that there are higher powers,
above the Ring, and they are beneficent -- and that help will come to those who
resist evil of their own will." That's precisely what he learned
from Tom, and proved to himself through his own long and hard experience; and
that's precisely why eventually he became a pacifist like
Tom.
“I dislike Allegory - the conscious and intentional allegory - yet any attempt to explain the purport of myth or fairytale must use allegorical language. (And, of course, the more 'life' a story has the more readily will it be susceptible of allegorical interpretations: while the better a deliberate allegory is made the more nearly will it be acceptable just as a story.)” (From Tolkien Letter # 131.)
Tips for posting in the Reading Room.
