When the neighbor first says, "Good fences make good neighbors," we know that we’ve heard this saying before. When he echoes it at the end of the poem, we realize that this saying was passed down to our neighbor from his father. In this way, the neighbor represents tradition and custom, relying on the past to serve as his guide. The speaker describes his neighbor as "an old-stone savage," making us think of a Neanderthal or caveman. In so doing, our speaker seems to challenge old-school methods, and paints a picture of the wall as antiquated or uncivilized.
The poem does not want us to side with the speaker and hate walls. The poem wants us to consider both sides of the wall argument.
The poem values innovation over tradition.