Limerick appears to be the only county in Ireland where there’s such a crossover between GAA and rugby football support. Other counties might have a small grouping who actively attend matches across hurling, football and rugby football. But it’s largely weirdos and proddies who solely go to rugby football matches. However, Limerick alone seems to have hundreds of die-hard GAA men and catholic mass goers who passionately follow Munster all over Europe.
This has been dealt with before. There was even a link to a thesis on the social history of City that discusses why soccer and rugby flourished in Limerick.
Success plays a part. Sadly Limerick GAA and Limerick FC have been in the doldrums for a long time and people naturally want to associate with something the has success and they used Munster rugger for this end, sadly.