Why is Robert Frost's poem called "The Road Not Taken" instead of "The Road Less Traveled"?

Robert Frost's poem "The Road Not Taken," the speaker says,

I shall be telling this with a sigh/Somewhere ages and ages hence:/Two roads diverged in a wood, and I--/I took the one less traveled by,/And that has made all the difference. 

In this final stanza of the poem, the contolling metaphor is not having gone one's individual way, but, rather, having departed from the allure of another way. That is, the speaker wonders how his life would have been different if he had gone down the road that he "kept...for another day."  Thus, the theme of Frost's poem is the rue of the speaker that he had not chosen another "path" in life, not that he "took the one less traveled."

This point of emphasis may be what draws many readers to Frost's poem.  For, so often people perceive the other road down which they could have gone in life as having more appeal later in their lives in light of their disappointments and "sighs" over their present states.