Ireland, as an island, have consistently produced some top quality footballing talent. It didn't just start with Ferguson.
From Blanchflower and Best to Roy and Robbie Keane. Keepers like Jennings, Bonner and now Bazunu and Kelleher.
Players like Niall Quinn, Richard Dunne, Stephen Ireland, Shay Given, Glenn Whelan, Kevin Horlock, Steve Lomas, Terry Phelan, Damien Duff, Steve Finnan, Shane Long, Dennis Irwin, Seamus Coleman, Paul McGrath, Matt Doherty, James McCarthy, John O'Shea, Johnny Evans, Kevin Kilbane, Steve Staunton, Aiden McGeady and Nathan Collins prove there is a constant stream of PL level players - with occasional world-class talents.
Investing in a club in Ireland would make sense IMO. The LOI is at a very low standard right now but could improve. That would mean it would take comparatively little investment to make a large impact. It would no doubt be a loss making venture at first but if the club can move the talent through the CFG pipeline they could make serious cash off some Irish talent. Say we buy Cork City, and a young Robbie Keane comes through - he may not be good enough for city but he could go to Troyes, Girona, NYCFC or another CFG side and increase their value. An Irish club would make an excellent haven for young loan players as well - as the level is low but physical and they speak English. It would be similar to owning a national league side in that way.
The talent is there - Gaelic football is not a meaningful competitor as you simply cannot make the same sort of living in GAA. The grassroots needs extra funding in Ireland but that could begin with a new CFG club. Also, Gaelic games are less easy to just play with your mates in a park.