Why would Frost write the poem: "In a Disused Graveyard" as an iambic tetrameter.?

The living come with grassy tread
To read the gravestones on the hill;
The graveyard draws the living still,
But never anymore the dead.
The verses in it say and say:
"The ones who living come today
To read the stones and go away
Tomorrow dead will come to stay."
So sure of death the marbles rhyme,
Yet can't help marking all the time
How no one dead will seem to come.
What is it men are shrinking from?
It would be easy to be clever
And tell the stones: Men hate to die
And have stopped dying now forever.
I think they would believe the lie.

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"In a Disused Graveyard" follows three poems that glance with various degrees of wistfulness at disappointed ideals that end in uncertainty or death. Here the speaker gently mocks people's unwillingness to die and gives stones the ability to see and say that death has ceased. The scene, however, is concrete: a New England graveyard no longer used because its community has faded. But visitors still come to read the tombstones, not out of affectionate attachment but out of curiosity. The attraction of these living by the dead emphasizes the contrast between vitality and arrest. The tombstones’ inscriptions speak of how those reading them must eventually join the dead. The tombstones' personification gently contrasts with their real incapacity, the speaker satirically focuses fear in the word "shrinking." At last he shifts voice and denies the kind of cleverness in which he has been engaging. He speculates that he could lie to the tombstones by expressing the human hope not to die as if that hope had become true, and he makes his strongest personification of the stones as dead people by sadly reflecting on the likelihood of fooling them. The last line radiates meanings: the stones "would believe the lie" because they know what fear is like (except that they know nothing), they would believe it because no one seems to join them anymore, and they would believe it because the speaker has projected his life-haunted feelings into them.