No contemporary response
As far as I can tell, there was no contemporary response to ‘Unkept Good Fridays’, and certainly no negative reaction of the kind suggested in the questions. As for the reasons, I can only speculate, but, for what little they are worth, here are my guesses.
The poem itself is ambiguous (and the last two lines difficult; see below) and does not have to be interpreted as an attack on Christianity. The idea that there are many forgotten saints and martyrs whose deaths resembled Christ’s is entirely conformable with Christian orthodoxy, as is the idea in the last stanza that the world was not worthy of these martyrs.
Hardy was out of fashion in 1928 when the poem was published. He had continued to write in late-Victorian style, and had not adopted the techniques of newer movements such as symbolism, imagism, and modernism. This made his works less attractive for critics to write about.
Few people read poetry and so it is simply not a threat to the establishment. Cases of criminal blasphemy in the 19th and early 20th centuries typically involved some element of campaigning or public agitating, as in the case of the atheistic periodical The Oracle of Reason, whose editors were imprisoned one by one in 1841–1843. The last person to be imprisoned for blasphemy in England, John William Gott in 1922, came to the attention of the authorities through his advocacy of birth control.
You’d need to be a Mary Whitehouse to think it a good idea to create a scandal over a poem that only a handful of people would have otherwise have read. If not for Whitehouse’s 1977 private prosecution of Gay News, hardly anyone would have heard of James Kirkup’s ‘The Love That Dares to Speak Its Name’.
Few later responses
I was unable to discover anything written about the poem prior to the 1970s. Presumably enough time had to pass for the poem to become of historical interest, rather than merely old-fashioned. Even then, critics have had little to say. Here are all the interesting comments I found:
‘Unkept Good Fridays’ was first published in the Daily Telegraph for April 5, 1928. Possibly the idea for the poem came to Hardy when, reading his Bible, he came upon a note written many years before at the head of the Book of Ezekiel: “Mar. 25, 1864. Good Friday.” Citing this note, Phelps says, “There is no clue to the association here, unless it was Hardy’s growing sense of the betrayal of Christ’s message by the idolatry and materialism of the age, at least equal in degree, if not in kind, to the targets of Ezekiel’s anger.”† Ezekiel’s targets include idolatry, false prophecy, sensual sins, pride, tyranny, and hypocrisy.
The poem memorializes the many nameless “men whom rulers slew / For their goodwill.” Perhaps Hardy had in mind not only the “heretics” of the medieval inquisitions but also the men of Dorchester condemned to death for non-conformity in Judge Jeffreys’s “bloody assizes.”
James Osler Bailey (1970). The Poetry of Thomas Hardy, p. 580. University of North Carolina Press.
† Kenneth Phelps (1966). Annotations by Thomas Hardy in his Bibles and Prayer-Book, p. 5. Toucan Press.
If Hardy had concluded with the fourth stanza, the poem might have remained a conventionalized and unsurprising statement of Christian doctrine: the good man is fated to be scorned, to live through ‘days of bonds and burning’; there are many Christs, and their Good Fridays will never be commemorated. But the fifth stanza goes much further, and argues that the failure to remember who they were really doesn’t matter: ‘The world was not even worthy / To taunt their hopes and aims…’ We have not been worthy of them or of Jesus. We have already dishonoured the memory of the Christ we knew. Why, then, should we assume that we could or would honour the memory of any of the nameless Christs—‘these Christs of unwrit names’—if in fact we were to be informed of the nobility of their individual moments on Calvary? The final message of Hardy’s poem is best characterized as bleak. Christ was, and remains today, too good for us. We rejected him, and all who followed in his footsteps, and we are where we are today because our Christianity is hollow. ‘Unkept Good Fridays’ can thus be read as a final comment on ‘Christmas in the Elgin Room’. The old gods are exiled, imprisoned in the British Museum, devitalized; but the god of Christianity, the true and living Christ, may never have been believed in, and even worse, it is not in human nature—as the New Dark Age moves in, engulfing us—to understand and appreciate the meaning of Good Friday.
Harold Orel (1975). ‘After The Dynasts: Hardy’s Relationship to Christianity’. In F. B. Pinion, ed. Budmouth Essays on Thomas Hardy, pp. 185–186. Thomas Hardy Society.
The poem seems to be the outcome of one of the Positivist beliefs, that in the cause of humanity Jesus was but one of many Messiahs or Redeemers. This view is expressed by Frederic Harrison† in The Positive Evolution of Religion (1913).‡
F. B. Pinion (1976). A Commentary on the Poems of Thomas Hardy, p. 239. London: Macmillan.
† “Frederic Harrison, a Positivist friend of Hardy who was a great Evolutionary optimist.” (Pinion, p. 163). He reviewed Hardy’s 1919 Collected Poems in The Fortnightly Review (February 1920), pp. 179–184.
‡ “But we know that Jesus was only one of many Messiahs, many Saviours, many Sons of Man, many Redeemers” (Harrison, p. 196).
Meaning of the last two lines
The last two lines are quite difficult. To make sense of the penultimate line we can suppose some elided words, for example:
[which were] as little of earth, [as little] earthy,
where “which” refers back to “their hopes and aims”, which were motivated by spiritual concerns, not earthly ones. If Hardy’s wording seems awkward, that’s because it alludes to 1 Corinthians 15:47 in the Authorized Version:
The first man* is of the earth, earthy:† the second man‡ is the Lord from heaven.
* Adam † The repetition here was in the original Greek (χοϊκός ἐκ γῆς) ‡ Christ
In the context of this allusion, “his” in the last line must mean “Adam’s”, so that “his mankind” means the descendants of Adam, that is, the whole of humanity. Putting all this together, the ideals of the forgotten martyrs had as little worldliness in them, as any ideals proclaimed by humanity.