Michael Cusack described himself as a "sterling lover of the game" (of rugby football). He also once said that cricket was Ireland's national game and every village and town should have a team.
What changed for Michael and Co was that he developed a bit of self loathing from hanging around a few too many Fenians - much like @ChocolateMice the soccer fan at Mary I. They wanted to take control and away from the Catholic Merchant classes and Anglo Irish who ran sports and had got too paly.
So himself a couple of others who had played rugby football and association football made up some sports. Took some ideas from here, took some ideas from there. A bit of myth from Ireland's history and a few hard rules from other sports.
The GGA claimed to never be a political organisation but that is a total lie. The efforts they went to in trying to monopolise sport in Ireland were outrageous. They drove schools like Blackrock away from their sports because they were so self loathing. Couldn't countenance a bit of international flavour in Ireland. Inward and insular looking weirdos.