Didn't they try a full schedule a few years ago and pull it because the market insisted on using EI in the morning and RE in the evening? If they had supported the twice-daily then, it may well have become something bigger by now. One is to assume RE's latest attempt to put a late afternoon service into place was to test if the air market actually still existed - it was clearly one "local business interests" wanted restored but obviously wasn't supported in the numbers needed, maybe because it left Dublin quite early in the afternoon or maybe because the train from Limierick has improved.
Time for Ryanair to pitch up to the bar on the route maybe ?