Irish gay marriage approval: why did "No's" vote that way?

CNN's post-referendum report is here and is far more faithful to the tenor of
the body politic than was NBC's tabloidy, gawking version

No one seems to want to pay for exit polls in the UK or Ireland, because either the media are too cheap or because their audience is willing to forgo U.S.-style immediate gratification and wait a few hours for poll workers to count the ballots.
     The Irish Times polled voters several times, right up to a week before the referendum and published the results. Following are responses to six questions probing voting attitudes about same sex marriage of both "yes" and "no" voters.

     The only constituency to reject marriage equality in Ireland (of 43) was Roscommon South Leitrim with 51.41% against (18,644 "no" and 17,615 "yes") and a 61.5% turnout. Nationally, the vote went the other way: 1,201,607 to 734,300 in favor (62%-38%).
     Roscommon's barely-prevailing attitude is now being subjected to everything from good-natured ribbing to a spit-roasting from other Irish. Even descendants of Roscommon stock, like American film star Tom Cruise have not been spared.
     "Rossies" have their reasons for being the most notoriously contrarian of Ireland's counties; a native, Patsy McGarry, explained them here.