Yes, seems like a strange route. But perhaps a different operator had already applied for a more direct route, probably Limerick -> Dublin City -> Dublin Airport.
Seems likely as it is crazy for Dublin Coach not to operate to Dublin Airport.
Their website could do with a lot of work, no ticket prices, no ability to buy tickets, no info if the buses have free wifi and onboard toilets, but looks like it will be coming soon.
Schedule looks good with wide ranging hourly service. Could do with an earlier departure from both Limerick and Dublin to get you into both before 9 and a late departure from Limerick to get you to Dublin Airport for early morning flights.
However delighted to see another good option like this open up for people. Seems to be some new bus license activity going on, hopefully we will see more for Cork and Waterford soon.
Again there may not be a sufficient demand for a non stop service any later.