Any time I'm abroad I use trains, it's the best way to travel. In Ireland they're too expensive and crowded, it's cheaper and more pleasant to drive and pay for parking. That's not great for the environment.
Why are they so expensive? At least in part because of free travel. Over 1m people have access to free travel, probably about 25%+ of the adult population.
Free travel means Irish Rail have had a free hand to demand price hikes. For Irish Rail they can charge what they like because a large section of their users simply don't care - the government is going to hand over the cash for them. (Many people don't understand how the system works - they genuinely think Irish Rail is letting them on for nothing).
Free travel is great for OAPs, but in a limited form - maybe off peak (like it used to be) and with a reasonable number of journeys per year before a reduced ticket price kicks in.