That didn't used to stop them.
Although, if they relaunched, they'd be a lot more dependent on the connecting market. Previously, the long-haul connections would have mixed with a lot of business passengers travelling with no bags whatsoever.
With the motorway completed and with the train now operating every hour and offering fully flexible tickets, there's not a huge amount of reason to fly to Dublin for leisure or business. Maybe if your destination was near the airport, but that's aboutit.