If my memory is correct Aer Arran tried to launch 2 or 3 routes maybe 5 years ago from Derry and the routes where scrapped before they even took off so they must have seen there wasn’t demand for a regional airline operating regularly all day. Flybe also tried MAN and that didn’t last either.
What LDY needs is local tour operators pushing for more charter flights in the summer and winter where the loads are guaranteed