LotR - Prologue

[Son of Númenor]

the phantom

It's right there in the Prologue that we're discussing, silly.

Actually, for the sake of accuracy, it says that hobbits are not stout and stocky (when compared with Dwarves).

Durelin

You say that the Hobbits formed Tolkien's 'ideal society', and yet you realize that there are some things that Tolkien finds un-ideal. It is interesting that, being so cut off from their own history and the outside world, that Tolkien would make them the center of his historical document, as well as the fictional authors. Could it be that bringing them so deeply into the goings on of the world, Tolkien was showing the Hobbits the light? Or was he trying to express that this was a great stain on the character and lives of the Hobbits? (italics mine)

You are implying, if I'm not mistaken, that the outside interaction of Frodo, Sam, Merry, Pippin and Bilbo could possibly have been viewed by Tolkien as a "great stain" upon the hobbits in question. I don't think that's a possibility. The hobbits in the Lord of the Rings who participated in some manner in the War of the Ring grew from their experience. They fought for their idyllic home and won. Sam, Merry and Pippin were able to return home wiser (and in the case of the latter two, merrier). Frodo and Bilbo outgrew the Shire, but this is not really a matter of staining so much as growth; in the course of Frodo's quest he reached a higher spiritual plane than could not be satisfied by a simple, agrarian place like the Shire. Bilbo, likewise, after all of his adventures and then the burden of having the Ring for all those years, outgrew his surroundings and 'retired' to live with the Elves. Both made the journey West (and ultimately Sam, too) not to be relieved of any 'stains', but to live out their lives in a place more suited to their spiritual needs.

The prologue, in my opinion, serves to highlight the idyllic, pastoral quality (and also the simpleness and 'smallness') of the Shire, perhaps even moreso than the actual book chapters that take place in the Shire. It lays the groundwork for why four hobbits are willing to fight to preserve their homeland, and ultimately serves as an illustration of why Frodo can never be at peace in the Shire after destroying the Ring.