The spirits of the Irish cannot be dampened on St. Patrick's Day

The following is a brief excerpt from an essay by James Thurber entitled "Take Her Up Tenderly." I have it in a book called "Thurber Country" which was copyrighted in 1953.

---
I have a bone to pick with the singing Andrews Sisters, known to their many friends as the Girls. A few years ago, with the assistance of a man named Hughie Prince, they made up their own version of "Sweet Molly Malone" and had it copyrighted. In this arrangement, Molly does not die or even get sick. The old ballad was public domain, and anybody can do what he wants with Molly, and almost everybody has.

As every barroom quartet knows, the authentic Molly Malone died of a fever, or "faver," and no one could save her, and that was the end of Sweet Molly Malone. It is a well-known fact in Dublin's fair city, and everywhere else, that her ghost wheels her barrow through street wide and narrow, crying "Cockles and mussels alive, alive, O!" The Girls didn't want to sing it that way. I have it on the authority of someone close to them that they don't like anything to be sad or anybody to die. Their song ends like this: "So they both wheel a barrow, through streets wide and narrow, the man that she wed and Sweet Molly Malone." It depressed me terribly when I heard the Girls sing it that way over the air one windy evening in 1950.
...
The day I heard the Andrews Sisters sing their sanguine version of the old ballad was March seventeenth, and I had thought for a while that the Girls kept Molly alive so as not to dampen the spirits of the Irish on St. Patrick's Day. I took this up with my friend John Aloysius McNulty, who said simply, "The spirits of the Irish cannot be dampened on St. Patrick's Day." I should have known that.