I think what needs to be understood is that any universal religion, is like the EU, there is a universal set of rules that all broadly agree with and then underneath, there are strong nations with their own culture and traditions.
We have seen this in the Muslim community, where muslims in this country come from a wide range of countries and those from each country bring with them, incorporated into their religion, a host of cultural practices that are particular to them. FGM, Honour killings and forced marriages are all associated with different cultural beliefs within the Muslim community.
Things are no different within the Christian community. The CofE has divergence on attitudes to homosexuality, which are as much driven by the cultural background of the countries involved as by their religious beliefs.
The catholic church is the same. The truly appalling things that happened in Ireland arise from the cultural background of the catholic religion in Ireland. Over the many centuries, the Irish people founght to hold on to their religious and cultural identity under the oppressive rule of the British. Not for nothing were the big (protestant) Anglo-Irish familes known as The Ascendency. From the early 17th century the British government encouraged the emigration of protestants to Ireland. I could go on about the oppression Irish catholics faced in their own country, but I won't.
This led to a fusion between nationality and religion, they became one and the same thing. Irish society developed into an inward looking group always defensive against any intruder. Priests became their leaders, because they were usually the only people with any education. To have a son who became a priest gave a family status.
Put these pressures, with the countries isolation on the far edge of Europe and this toxic brew produced Irish catholicism, insular, and religiously obsessed. To break any of the rules was to reject your community and they knew what to do with people like that.
Terrible things happened in the name of religion in Ireland. I am no apologist for them, but these institutions were only in Ireland. They were not universal, they did not exist in England or other countries.
As PippaZ says It is hard to remember just how stifling societies rules were in the early twentieth century. and I would add most certainly in the 19th century.
I am half Irish on both sides of my family.