The trouble with rail freight today is that we have long passed the tipping point, yards and gantries swept away, staff gone, sidings gone, wagons gone, locomotives..blah, blah, blah. It has little to do with distances being too short or the so-called motorway network and more to do with the State paying lip service to the railways, carbon emissions etc.etc. blah, blah.
Light industry simply has no need for rail freight and it is very hard to justify the cost of maintaining those yards, gantries, sidings, wagons, locos, trackbeds, staff for how little heavy industry we have. There just isn't the scale to justify it, specially when you can just roll a truck up to your factory load it up and have your freight anywhere in Ireland in just 3 to 4 hours.
The environmental argument is also pretty weak. After all rail freight locos use the same Diesel that trucks do and in fact trucks most meet much stricter pollution regulations (Euro 5 and 6 engines) then old rail freight locos which likely have zero filtration.