The county Cork has a reputation of fostering rebels, for example the legendary 3rd brigade of the IRA, under the command of Tom Barry. They got their reputation during the fighting against the British paramilitary Black and Tans in the early 20s. It's natural to find the National Monument, with statues of the freedom fighters, in the city of Cork. It may look like a paradox that many of the great Irish nationalists were Protestants, some even had English background. People like Jonathan Swift, Wolfe Tone, Robert Emmet, CS Parnell and WB Yeats were Protestants who opposed the British rule.
People act according to their beliefs and material circumstances.
Sometimes the borders between people follow the religious line and sometimes not. The conflict in Northern Ireland must not be reduced to a mere question of different religions. In the province of Ulster we witness the sad remainders of many centuries of British imperial ambitions.