Why does Frost repeat the phrase “Good fences make good neighbors”?

Frost's neighbor repeats the phrase "Good fences make good neighbors"  twice:

1. Frost tells his neighbor that a man-made wall is not necessary because their boundaries are naturally and clearly demarcated as Frost grows apple trees in his plot of land whereas pine trees are growing in his neighbor's. But his neighbor refuses to accept Frost's logical argument. He is simply incapable of reasoning because he is blinded by the dogma and tradition of what his forefathers have drummed into him over the years.

2. Having failed to reason logically and convince his neighbor that the wall is not necessary he hopes that his neighbor will atleast intuitively understand that "Something there is that doesn't love a wall/That wants it down." Every Spring, Frost and his neigbor meet to rebuild the broken wall. This is an annual ritual which both of them have performed routinely for many years. Frost is now an enlightened person who clearly understands the futility of this annual ritual. Frost hopes that his neigbor will also instinctively  gain this same knowledge and understanding. But no such flash of inspiration or intuition can penetrate into his neighbor who resembles a stone age savage completely blinded by dogma and tradtion and who smugly repeats,"Good fences make good neighbors."

Frost repeats this cliche twice to foreground the fact that  logical reasoning and  intuitive inspiration were both unsuccessful in enlightening his neighbor.