Lads got into a heated debate about this last night, and unfortunately because i was sorta seeing red i didnt actually debate the facts as they were. Anyway, the lads were saying that only in connaught is rugby not big, and you have clubs throughout the country. The reason soccer is a bigger participation sport is cos of 5 a sides and how much easier it is for 10 or 22 lads to just go out on a pitch having potentially never played before - organisation i spose - which is fair enough in terms of rugby we couldn't all just decide to go out and play rugby when we hadn't played before etc. The other argument was if Ireland were playing in croke park it would be full, i tried to suggest the novelty factor etc, but then they came back with well how did Italy sell out last year, which I didnt think about, but had an answer about 5 mins later when it was too late. Finally, my finsihing arguement(but i was too young as i didnt go to rugby and couldn't gauge the general consensus in Ireland at the time) was that Rugby wasn't as popular 10 years ago and soccer was, because irish "sports" people are a fickle bunch and only got into rugby in the last few years due to the popularity factor, the munster factor, and the fact that Ireland are actually a decent team now. Growing up I would watch soccer and rugby the whole time, but the big rugby games would always be more entertaining to watch in fairness as a sporting spectacle.
Anyway on the Italy thing, i reckon its far cooler to say you were in croker watching rugby and with the lads or in the box or what not than it is for soccer. Also rugby matches are far less a year and therefore every game is almost like a key qualifier match in terms of soccer. Also six nations occurs when generally not much other sport of note going on, and lastly, the six nations is always on a weekend and is well supported by visiting nations.