what is ironic about the conclusion of "A Modest Proposal"?

Irony

.......The dominant figure of speech in "A Modest Proposal" is verbal irony, in which a writer or speaker says the opposite of what he means. Swift's masterly use of this device makes his main argument—that the Irish deserve better treatment from the English—powerful and dreadfully amusing. For example, to point out that the Irish should not be treated like animals, Swift compares them to animals, as in this example: "I rather recommend buying the children alive, and dressing them hot from the knife, as we do roasting pigs." Also, to point out that disease, famine, and substandard living conditions threaten to kill great numbers of Irish, Swift cheers their predicament as a positive development:

Some persons of a desponding spirit are in great concern about that vast number of poor people, who are aged, diseased, or maimed, and I have been desired to employ my thoughts what course may be taken to ease the nation of so grievous an encumbrance. But I am not in the least pain upon that matter, because it is very well known that they are every day dying and rotting by cold and famine, and filth and vermin, as fast as can be reasonably expected. And as to the young laborers, they are now in as hopeful a condition; they cannot get work, and consequently pine away for want of nourishment, to a degree that if at any time they are accidentally hired to common labor, they have not strength to perform it; and thus the country and themselves are happily delivered from the evils to come.