I'm not so sure that abuse didn't happen elsewhere. Ireland had (and in some respects still has) a strong culture of amateurism when it comes to management, and that had/has repercussions for all institutions where there were vulnerable people -- old folks homes (especially county homes), county hospitals, maternity hospitals, all schools, and senior management who had got there by the time-honoured methods of timeserving and never sticking your neck out.
Nuns and brothers or priests were never trained to be managers. Their training consisted of spiritual elements only, with maybe a bit of bookkeeping thrown in. Modern psychological insight into human behaviour was considered one of the main moral problems in the twentieth century (Freud's ideas about the major drives shared by humanity being anathema to people raised on the Catechism which postulates a completely different function for humans), and management practices/group psychology arising from the science of psychology never made a dent in any of the Orders' training for teachers or managers, whether in healthcare of education.
Freud and the Catechism are uneasy bedfellows and even today the prevailing atmosphere in convent schools tends to be the old suck up culture that led to acceptance of horrible abuse as a part of life that you just had to get used to. Teachers have favourites and no-one raises an eyebrow, enthusiastic young teachers find the life sucked out of them not by sullen children but by horribly unprofessional management practices, the head nun tends to be 'she who must be obeyed', and can often be a talentless timeserver in a dwindling group of available nuns whose time has come and who is interested only in making sure everyone knows who the Boss is but is otherwise not at all interested in institutional development or the welfare of the children - rather than someone actually able to manage staff properly, keep morale up among staff, introduce new ideas, above all end the suck up culture so beloved of the nuns that is such a cancer in Irish schools. [I do have one specific well regarded convent school in mind here]