The other Irish schools don't hold them for the Irish students either.
The premises as I understand are:
(A) In Ireland, there is too much of an old boy's network. You let in my son, I'll let in your daughter. When the Irish class is selected by pure numbers on the leaving cert, yes there may be more than a handful of second generation doctors but they got there on a test for merit, which while suboptimal, is at least better than just who they knew or who their parents are.
(B) Some committee in charge of this had an interview with an Irish paper a few years back. They said that in the current era, there are many careers in medicine; not everyone going into medicine needs to be a great interviewer that aces a verbal interview. You could go into pathology/radiology/other specialities that have less patient face time, do a research path, or do business/administration.
(C) There is a school of thought that there are 3 rules of interviews: (1) Interviews don't work. (2) Interviews don't work. (3) Interviews don't work. People are coached and say what people want to hear. Schools that are trying to set a cutting edge for admissions, like McMaster in Canada, are throwing out the interview since it is felt to be suboptimal and trying things like a speed-dating kind of format instead.